Rocco Rutte:

[apps/madmutt.git] / doc / manual.sgml.head

<!-- vim:ft=sgml
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<!doctype linuxdoc system>

<book>

<title>The Mutt Next Generation E-Mail Client
<author>by Andreas Krennmair <htmlurl url="mailto:ak@synflood.at" name="&lt;ak@synflood.at&gt;"> and others
        originally based on <em>mutt</em> by Michael Elkins <htmlurl url="mailto:me@cs.hmc.edu" name="&lt;me@cs.hmc.edu&gt;"> and others
<date>version @VERSION@
<abstract>
Michael Elinks on mutt, circa 1995: ``All mail clients suck. 
This one just sucks less.'' - Sven Guckes on mutt, ca. 2003: ``But it still sucks!''
</abstract>

<toc>

<chapt>Introduction <!--{{{--> 

<sect>Overview <!--{{{--> 
<p>
<bf/Mutt-ng/ is a small but very powerful text-based MIME mail client.  Mutt-ng is
highly configurable, and is well suited to the mail power user with advanced
features like key bindings, keyboard macros, mail threading, regular
expression searches and a powerful pattern matching language for selecting
groups of messages.

<p>This documentation additionally contains documentation to <bf/Mutt-NG/, a 
fork from Mutt with the goal to fix all the little annoyances of Mutt, to
integrate all the Mutt patches that are floating around in the web, and to
add other new features. Features specific to Mutt-ng will be discussed in
an extra section. Don't be confused when most of the documentation talk about
Mutt and not Mutt-ng, Mutt-ng contains all Mutt features, plus many more.

<!--}}}--> 

<sect>Mutt-ng Home Page <!--{{{--> 
<p>
<htmlurl url="http://www.muttng.org/"
name="http://www.muttng.org">

<!--}}}--> 

<sect>Mailing Lists <!--{{{--> 
<p>

<itemize>
<item><htmlurl url="https://lists.berlios.de/mailman/listinfo/mutt-ng-users"
name="mutt-ng-users@lists.berlios.de"> -- This is where the mutt-ng user support happens.
<item><htmlurl url="https://lists.berlios.de/mailman/listinfo/mutt-ng-devel" name="mutt-ng-devel@lists.berlios.de"> -- The development mailing list for mutt-ng
</itemize>

<!--}}}--> 

<sect>Software Distribution Sites <!--{{{--> 
<p>
So far, there are no official releases of Mutt-ng, but you can download
daily snapshots from <htmlurl url="http://mutt-ng.berlios.de/snapshots/" name="http://mutt-ng.berlios.de/snapshots/">

<!--}}}--> 

<sect>IRC <!--{{{--> 
<p>
Visit channel <em/#muttng/ on <htmlurl
url="http://www.freenode.net/" name="irc.freenode.net
(www.freenode.net)"> to chat with other people interested in Mutt-ng.

<!--}}}--> 

<sect>Weblog <!--{{{--> 
<p>
If you want to read fresh news about the latest development in Mutt-ng, and get informed
about stuff like interesting, Mutt-ng-related articles and packages for your favorite
distribution, you can read and/or subscribe to our 
<htmlurl url="http://mutt-ng.supersized.org/" name="Mutt-ng development weblog">.

<!--}}}--> 

<sect>Copyright <!--{{{--> 
<p>
Mutt is Copyright (C) 1996-2000 Michael R. Elkins
&lt;me@cs.hmc.edu&gt; and others

This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.

This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111, USA.

<!--}}}--> 

<!--}}}--> 

<chapt>Getting Started <!--{{{--> 

  <sect>Basic Concepts <!--{{{--> 

    <sect1>Screens and Menus <!--{{{--> 

      <p>mutt-ng offers different screens of which every has its special
      purpose:

      <itemize>

        <item>The <em/index/ displays the contents of the currently opened
        mailbox.

        <item>The <em/pager/ is responsible for displaying messages, that
        is, the header, the body and all attached parts.

        <item>The <em/file browser/ offers operations on and displays
        information of all folders mutt-ng should watch for mail.

        <item>The <em/sidebar/ offers a permanent view of which mailboxes
        contain how many total, new and/or flagged mails.

        <item>The <em/help screen/ lists for all currently available
        commands how to invoke them as well as a short description.

        <item>The <em/compose/ menu is a comfortable interface take last
        actions before sending mail: change subjects, attach files, remove
        attachements, etc.

        <item>The <em/attachement/ menu gives a summary and the tree
        structure of the attachements of the current message.

        <item>The <em/alias/ menu lists all or a fraction of the aliases
        a user has defined.

        <item>The <em/key/ menu used in connection with encryption lets
        users choose the right key to encrypt with.

      </itemize>

      <p>When mutt-ng is started without any further options, it'll open
      the users default mailbox and display the index.

    <!--}}}--> 

    <sect1>Configuration <!--{{{--> 

      <p>Mutt-ng does <em/not/ feature an internal configuration
      interface or menu due to the simple fact that this would be too
      complex to handle (currently there are several <em/hundred/
      variables which fine-tune the behaviour.)

      <p>Mutt-ng is configured using configuration files which allow
      users to add comments or manage them via version control systems
      to ease maintenance.

      <p>Also, mutt-ng comes with a shell script named <tt/grml-muttng/
      kindly contributed by users which really helps and eases the
      creation of a user's configuration file. When downloading the
      source code via a snapshot or via subversion, it can be found in
      the <tt/contrib/ directory.

    <!--}}}--> 

    <sect1>Functions <!--{{{--> 

      <p>Mutt-ng offers great flexibility due to the use of functions:
      internally, every action a user can make mutt-ng perform is named
      ``function.'' Those functions are assigned to keys (or even key
      sequences) and may be completely adjusted to user's needs. The
      basic idea is that the impatient users get a very intuitive
      interface to start off with and advanced users virtually get no
      limits to adjustments.

    <!--}}}--> 

    <sect1>Interaction <!--{{{--> 

      <p>Mutt-ng has two basic concepts of user interaction:

        <enum>

          <item>There is one dedicated line on the screen used to query
          the user for input, issue any command, query variables and
          display error and informational messages. As for every type of
          user input, this requires manual action leading to the need of
          input.

          <item>The automatized interface for interaction are the so
          called <em/hooks/. Hooks specify actions the user wants to be
          performed at well-defined situations: what to do when entering
          which folder, what to do when displaying or replying to what
          kind of message, etc. These are optional, i.e. a user doesn't
          need to specify them but can do so.

        </enum>

    <!--}}}--> 

    <sect1>Modularization <!--{{{--> 

      <p>Although mutt-ng has many functionality built-in, many
      features can be delegated to external tools to increase
      flexibility: users can define programs to filter a message through
      before displaying, users can use any program they want for
      displaying a message, message types (such as PDF or PostScript)
      for which mutt-ng doesn't have a built-in filter can be rendered
      by arbitrary tools and so forth. Although mutt-ng has an alias
      mechanism built-in, it features using external tools to query for
      nearly every type of addresses from sources like LDAP, databases
      or just the list of locally known users.

    <!--}}}--> 

    <sect1>Patterns <!--{{{--> 

      <p>Mutt-ng has a built-in pattern matching ``language'' which is
      as widely used as possible to present a consistent interface to
      users. The same ``pattern terms'' can be used for searching,
      scoring, message selection and much more.

    <!--}}}--> 

  <!--}}}--> 

  <sect>Screens and Menus <!--{{{--> 

    <sect1>Index <!--{{{--> 

     <p>The index is the screen that you usually see first when you
     start mutt-ng. It gives an overview over your emails in the
     currently opened mailbox. By default, this is your system mailbox.
     The information you see in the index is a list of emails, each with
     its number on the left, its flags (new email, important email,
     email that has been forwarded or replied to, tagged email, ...),
     the date when email was sent, its sender, the email size, and the
     subject. Additionally, the index also shows thread hierarchies:
     when you reply to an email, and the other person replies back, you
     can see the other's person email in a "sub-tree" below.  This is
     especially useful for personal email between a group of people or
     when you've subscribed to mailing lists.

    <!--}}}--> 

    <sect1>Pager <!--{{{--> 

     <p>The pager is responsible for showing the email content. On the
     top of the pager you have an overview over the most important email
     headers like the sender, the recipient, the subject, and much more
     information. How much information you actually see depends on your
     configuration, which we'll describe below.

     <p>Below the headers, you see the email body which usually contains
     the message. If the email contains any attachments, you will see
     more information about them below the email body, or, if the
     attachments are text files, you can view them directly in the
     pager.

     <p>To give the user a good overview, it is possible to configure
     mutt-ng to show different things in the pager with different
     colors. Virtually everything that can be described with a regular
     expression can be colored, e.g. URLs, email addresses or smileys.

     <!--}}}--> 

    <sect1>File Browser <!--{{{--> 

      <p>The file browser is the interface to the local or remote
      file system. When selecting a mailbox to open, the browser allows
      custom sorting of items, limiting the items shown by a regular
      expression and a freely adjustable format of what to display in
      which way. It also allows for easy navigation through the
      file system when selecting file(s) to attach to a message, select
      multiple files to attach and many more.

    <!--}}}--> 

    <sect1>Sidebar <!--{{{--> 

      <p>The sidebar comes in handy to manage mails which are spread
      over different folders. All folders users setup mutt-ng to watch
      for new mail will be listed. The listing includes not only the
      name but also the number of total messages, the number of new and
      flagged messages. Items with new mail may be colored different
      from those with flagged mail, items may be shortened or compress
      if they're they to long to be printed in full form so that by
      abbreviated names, user still now what the name stands for.

    <!--}}}--> 

    <sect1>Help <!--{{{--> 

      <p>The help screen is meant to offer a quick help to the user. It
      lists the current configuration of key bindings and their
      associated commands including a short description, and currently
      unbound functions that still need to be associated with a key
      binding (or alternatively, they can be called via the mutt-ng
      command prompt).

    <!--}}}--> 

      <sect1>Compose Menu <!--{{{--> 

        <p>The compose menu features a split screen containing the
        information which really matter before actually sending a
        message by mail or posting an article to a newsgroup: who gets
        the message as what (recipient, newsgroup, who gets what kind of
        copy). Additionally, users may set security options like
        deciding whether to sign, encrypt or sign and encrypt a message
        with/for what keys.

        <p>Also, it's used to attach messages, news articles or files to
        a message, to re-edit any attachment including the message
        itself.

      <!--}}}--> 

      <sect1>Alias Menu <!--{{{--> 

        <p>The alias menu is used to help users finding the recipients
        of messages. For users who need to contact many people, there's
        no need to remember addresses or names completely because it
        allows for searching, too. The alias mechanism and thus the
        alias menu also features grouping several addresses by a shorter
        nickname, the actual alias, so that users don't have to select
        each single recipient manually.

      <!--}}}--> 

      <sect1>Attachment Menu <!--{{{--> 

        <p>As will be later discussed in detail, mutt-ng features a good
        and stable MIME implementation, that is, is greatly supports
        sending and receiving messages of arbitrary type. The
        attachment menu displays a message's structure in detail: what
        content parts are attached to which parent part (which gives a
        true tree structure), which type is of what type and what size.
        Single parts may saved, deleted or modified to offer great and
        easy access to message's internals.

      <!--}}}--> 

      <sect1>Key Menu <!--{{{--> 

        <p><tt/FIXME/

      <!--}}}--> 

  <!--}}}--> 

<sect>Moving Around in Menus <!--{{{--> 
<p>

Information is presented in menus, very similar to ELM.  Here is a table
showing the common keys used to navigate menus in Mutt-ng.

<tscreen><verb>
j or Down       next-entry      move to the next entry
k or Up         previous-entry  move to the previous entry
z or PageDn     page-down       go to the next page
Z or PageUp     page-up         go to the previous page
= or Home       first-entry     jump to the first entry
* or End        last-entry      jump to the last entry
q               quit            exit the current menu
?               help            list all key bindings for the current menu
</verb></tscreen>

<!--}}}--> 

<sect>Editing Input Fields<label id="editing"> <!--{{{--> 
<p>
Mutt-ng has a builtin line editor which is used as the primary way to input
textual data such as email addresses or filenames.  The keys used to move
around while editing are very similar to those of Emacs.

<tscreen><verb>
^A or <Home>    bol             move to the start of the line
^B or <Left>    backward-char   move back one char
Esc B           backward-word   move back one word
^D or <Delete>  delete-char     delete the char under the cursor
^E or <End>     eol             move to the end of the line
^F or <Right>   forward-char    move forward one char
Esc F           forward-word    move forward one word
<Tab>           complete        complete filename or alias
^T              complete-query  complete address with query
^K              kill-eol        delete to the end of the line
ESC d           kill-eow        delete to the end of the word
^W              kill-word       kill the word in front of the cursor
^U              kill-line       delete entire line
^V              quote-char      quote the next typed key
<Up>            history-up      recall previous string from history
<Down>          history-down    recall next string from history
<BackSpace>     backspace       kill the char in front of the cursor
Esc u           upcase-word     convert word to upper case
Esc l           downcase-word   convert word to lower case
Esc c           capitalize-word capitalize the word
^G              n/a             abort
<Return>        n/a             finish editing
</verb></tscreen>

You can remap the <em/editor/ functions using the <ref id="bind" name="bind">
command.  For example, to make the <em/Delete/ key delete the character in
front of the cursor rather than under, you could use

<tt/bind editor &lt;delete&gt; backspace/

<!--}}}--> 

<sect>Reading Mail - The Index and Pager <!--{{{--> 
<p>

Similar to many other mail clients, there are two modes in which mail is
read in Mutt-ng.  The first is the index of messages in the mailbox, which is
called the ``index'' in Mutt-ng.  The second mode is the display of the
message contents.  This is called the ``pager.''

The next few sections describe the functions provided in each of these
modes.

<sect1>The Message Index
<p>

<tscreen><verb>
c               change to a different mailbox
ESC c           change to a folder in read-only mode
C               copy the current message to another mailbox
ESC C           decode a message and copy it to a folder
ESC s           decode a message and save it to a folder
D               delete messages matching a pattern
d               delete the current message
F               mark as important
l               show messages matching a pattern
N               mark message as new
o               change the current sort method
O               reverse sort the mailbox
q               save changes and exit
s               save-message
T               tag messages matching a pattern
t               toggle the tag on a message
ESC t           toggle tag on entire message thread
U               undelete messages matching a pattern
u               undelete-message
v               view-attachments
x               abort changes and exit
<Return>        display-message
<Tab>           jump to the next new message
@               show the author's full e-mail address
$               save changes to mailbox
/               search
ESC /           search-reverse
^L              clear and redraw the screen
^T              untag messages matching a pattern
</verb></tscreen>

<sect2>Status Flags
<p>

In addition to who sent the message and the subject, a short summary of
the disposition of each message is printed beside the message number.
Zero or more of the following ``flags'' may appear, which mean:

<p>
<descrip>
<tag/D/ message is deleted (is marked for deletion)
<tag/d/ message have attachments marked for deletion
<tag/K/ contains a PGP public key
<tag/N/ message is new
<tag/O/ message is old
<tag/P/ message is PGP encrypted
<tag/r/ message has been replied to
<tag/S/ message is signed, and the signature is succesfully verified
<tag/s/ message is signed
<tag/!/ message is flagged
<tag/*/ message is tagged
</descrip>

Some of the status flags can be turned on or off using
<itemize>
<item><bf/set-flag/ (default: w)
<item><bf/clear-flag/ (default: W)
</itemize>

<p>
Furthermore, the following flags reflect who the message is addressed
to.  They can be customized with the
<ref id="to_chars" name="&dollar;to&lowbar;chars"> variable.

<p>
<descrip>
<tag/+/ message is to you and you only
<tag/T/ message is to you, but also to or cc'ed to others
<tag/C/ message is cc'ed to you
<tag/F/ message is from you
<tag/L/ message is sent to a subscribed mailing list
</descrip>

<sect1>The Pager
<p>

By default, Mutt-ng uses its builtin pager to display the body of messages.
The pager is very similar to the Unix program <em/less/ though not nearly as
featureful.

<tscreen><verb>
<Return>        go down one line
<Space>         display the next page (or next message if at the end of a message)
-               go back to the previous page
n               search for next match
S               skip beyond quoted text
T               toggle display of quoted text
?               show key bindings
/               search for a regular expression (pattern)
ESC /           search backwards for a regular expression
\               toggle search pattern coloring
^               jump to the top of the message
</verb></tscreen>

In addition, many of the functions from the <em/index/ are available in
the pager, such as <em/delete-message/ or <em/copy-message/ (this is one
advantage over using an external pager to view messages).

Also, the internal pager supports a couple other advanced features. For
one, it will accept and translate the ``standard'' nroff sequences for
bold and underline. These sequences are a series of either the letter,
backspace (^H), the letter again for bold or the letter, backspace,
``&lowbar;'' for denoting underline. Mutt-ng will attempt to display these
in bold and underline respectively if your terminal supports them. If
not, you can use the bold and underline <ref id="color" name="color">
objects to specify a color or mono attribute for them.

Additionally, the internal pager supports the ANSI escape sequences for
character attributes.  Mutt-ng translates them into the correct color and
character settings.  The sequences Mutt-ng supports are:

<p>
<tscreen><verb>
ESC [ Ps;Ps;Ps;...;Ps m
where Ps =
0    All Attributes Off
1    Bold on
4    Underline on
5    Blink on
7    Reverse video on
3x   Foreground color is x
4x   Background color is x

Colors are
0    black
1    red
2    green
3    yellow
4    blue
5    magenta
6    cyan
7    white
</verb></tscreen>

Mutt-ng uses these attributes for handling text/enriched messages, and they
can also be used by an external <ref id="auto_view" name="autoview">
script for highlighting purposes.  <bf/Note:/ If you change the colors for your
display, for example by changing the color associated with color2 for
your xterm, then that color will be used instead of green.

<sect1>Threaded Mode<label id="threads">
<p>
When the mailbox is <ref id="sort" name="sorted"> by <em/threads/, there are
a few additional functions available in the <em/index/ and <em/pager/ modes.

<tscreen><verb>
^D      delete-thread           delete all messages in the current thread
^U      undelete-thread         undelete all messages in the current thread
^N      next-thread             jump to the start of the next thread
^P      previous-thread         jump to the start of the previous thread
^R      read-thread             mark the current thread as read
ESC d   delete-subthread        delete all messages in the current subthread
ESC u   undelete-subthread      undelete all messages in the current subthread
ESC n   next-subthread          jump to the start of the next subthread
ESC p   previous-subthread      jump to the start of the previous subthread
ESC r   read-subthread          mark the current subthread as read
ESC t   tag-thread              toggle the tag on the current thread
ESC v   collapse-thread         toggle collapse for the current thread
ESC V   collapse-all            toggle collapse for all threads
P       parent-message          jump to parent message in thread
</verb></tscreen>

<bf/Note:/ Collapsing a thread displays only the first message
in the thread and hides the others. This is useful when threads
contain so many messages that you can only see a handful of threads on
the screen. See %M in <ref id="index_format"name="&dollar;index&lowbar;format">.
For example, you could use "&percnt;?M?(#&percnt;03M)&amp;(&percnt;4l)?" in <ref
id="index_format"name="&dollar;index&lowbar;format"> to optionally
display the number of hidden messages if the thread is collapsed.

See also: <ref id="strict_threads" name="&dollar;strict&lowbar;threads">.

<sect1>Miscellaneous Functions
<p><bf/create-alias/<label id="create-alias"> (default: a)<newline>

Creates a new alias based upon the current message (or prompts for a
new one).  Once editing is complete, an <ref id="alias" name="alias">
command is added to the file specified by the <ref id="alias_file"
name="&dollar;alias&lowbar;file"> variable for future use. <bf/Note:/
Specifying an <ref id="alias_file" name="&dollar;alias&lowbar;file">
does not add the aliases specified there-in, you must also <ref
id="source" name="source"> the file.

<p><bf/check-traditional-pgp/<label id="check-traditional-pgp"> (default: ESC P)<newline>

This function will search the current message for content signed or
encrypted with PGP the "traditional" way, that is, without proper
MIME tagging.  Technically, this function will temporarily change
the MIME content types of the body parts containing PGP data; this
is similar to the <ref id="edit-type" name="edit-type"> function's
effect.


<p><bf/display-toggle-weed/<label id="display-toggle-weed"> (default: h)<newline>

Toggles the weeding of message header fields specified by <ref id="ignore"
name="ignore"> commands.

<p><bf/edit/<label id="edit"> (default: e)<newline>

This command (available in the ``index'' and ``pager'') allows you to
edit the raw current message as it's present in the mail folder.
After you have finished editing, the changed message will be
appended to the current folder, and the original message will be
marked for deletion.

<p><bf/edit-type/<label id="edit-type"><newline>
(default: ^E on the attachment menu, and in the pager and index menus; ^T on the
compose menu)

This command is used to temporarily edit an attachment's content
type to fix, for instance, bogus character set parameters.  When
invoked from the index or from the pager, you'll have the
opportunity to edit the top-level attachment's content type.  On the
<ref id="attach_menu" name="attachment menu">, you can change any
attachment's content type. These changes are not persistent, and get
lost upon changing folders.

Note that this command is also available on the <ref
id="compose_menu" name="compose menu">.  There, it's used to
fine-tune the properties of attachments you are going to send.

<p><bf/enter-command/<label id="enter-command"> (default: ``:'')<newline>

This command is used to execute any command you would normally put in a
configuration file.  A common use is to check the settings of variables, or
in conjunction with <ref id="macro" name="macros"> to change settings on the
fly.

<p><bf/extract-keys/<label id="extract-keys"> (default: ^K)<newline>

This command extracts PGP public keys from the current or tagged
message(s) and adds them to your PGP public key ring.

<p><bf/forget-passphrase/<label id="forget-passphrase"> (default:
^F)<newline> 

This command wipes the passphrase(s) from memory. It is useful, if
you misspelled the passphrase.

<p><bf/list-reply/<label id="list-reply"> (default: L)<newline>

Reply to the current or tagged message(s) by extracting any addresses which
match the regular expressions given by the <ref id="lists" name="lists or subscribe">
commands, but also honor any <tt/Mail-Followup-To/ header(s) if the
<ref id="honor_followup_to" name="&dollar;honor&lowbar;followup&lowbar;to">
configuration variable is set.  Using this when replying to messages posted
to mailing lists helps avoid duplicate copies being sent to the author of
the message you are replying to.

<bf/pipe-message/<label id="pipe-message"> (default: |)<newline>

Asks for an external Unix command and pipes the current or
tagged message(s) to it.  The variables <ref id="pipe_decode"
name="&dollar;pipe&lowbar;decode">, <ref id="pipe_split"
name="&dollar;pipe&lowbar;split">, <ref id="pipe_sep"
name="&dollar;pipe&lowbar;sep"> and <ref id="wait_key"
name="&dollar;wait&lowbar;key"> control the exact behavior of this
function.

<bf/resend-message/<label id="resend-message"> (default: ESC e)<newline>

With resend-message, mutt takes the current message as a template for a
new message.  This function is best described as "recall from arbitrary
folders".  It can conveniently be used to forward MIME messages while
preserving the original mail structure. Note that the amount of headers
included here depends on the value of the <ref id="weed" name="&dollar;weed">
variable.

This function is also available from the attachment menu. You can use this
to easily resend a message which was included with a bounce message
as a message/rfc822 body part.

<bf/shell-escape/<label id="shell-escape"> (default: !)<newline>

Asks for an external Unix command and executes it.  The <ref
id="wait_key" name="&dollar;wait&lowbar;key"> can be used to control
whether Mutt-ng will wait for a key to be pressed when the command returns
(presumably to let the user read the output of the command), based on
the return status of the named command.

<bf/toggle-quoted/<label id="toggle-quoted"> (default: T)<newline>

The <em/pager/ uses the <ref id="quote_regexp"
name="&dollar;quote&lowbar;regexp"> variable to detect quoted text when
displaying the body of the message.  This function toggles the display
of the quoted material in the message.  It is particularly useful when
are interested in just the response and there is a large amount of
quoted text in the way.

<bf/skip-quoted/<label id="skip-quoted"> (default: S)<newline>

This function will go to the next line of non-quoted text which come
after a line of quoted text in the internal pager.

<!--}}}--> 

<sect>Sending Mail <!--{{{--> 
<p>

The following bindings are available in the <em/index/ for sending
messages.

<tscreen><verb>
m       compose         compose a new message
r       reply           reply to sender
g       group-reply     reply to all recipients
L       list-reply      reply to mailing list address
f       forward         forward message
b       bounce          bounce (remail) message
ESC k   mail-key        mail a PGP public key to someone
</verb></tscreen>

Bouncing a message sends the message as is to the recipient you
specify.  Forwarding a message allows you to add comments or
modify the message you are forwarding.  These items are discussed
in greater detail in the next chapter <ref id="forwarding_mail"
name="``Forwarding and Bouncing Mail''">.

<sect1>Composing new messages <!--{{{--> 

<p>When you want to send an email using mutt-ng, simply press <tt/m/ on
your keyboard. Then, mutt-ng asks for the recipient via a prompt in
the last line:

<verb>
To: 
</verb>

<p>After you've finished entering the recipient(s), press return. If you
want to send an email to more than one recipient, separate the email
addresses using the comma "<tt/,/". Mutt-ng then asks you for the email
subject. Again, press return after you've entered it. After that, mutt-ng
got the most important information from you, and starts up an editor
where you can then enter your email.

<p>The editor that is called is selected in the following way: you
can e.g. set it in the mutt-ng configuration:

<verb>
set editor = "vim +/^$/ -c ':set tw=72'"
set editor = "nano"
set editor = "emacs"
</verb>

<p>If you don't set your preferred editor in your configuration, mutt-ng
first looks whether the environment variable <tt/$VISUAL/ is set, and if
so, it takes its value as editor command. Otherwise, it has a look
at <tt/$EDITOR/ and takes its value if it is set. If no editor command
can be found, mutt-ng simply assumes <tt/vi/ to be the default editor,
since it's the most widespread editor in the Unix world and it's pretty
safe to assume that it is installed and available.

<p>When you've finished entering your message, save it and quit your 
editor. Mutt-ng will then present you with a summary screen, the compose menu. 
On the top, you see a summary of the most important available key commands.
Below that, you see the sender, the recipient(s), Cc and/or Bcc 
recipient(s), the subject, the reply-to address, and optionally
information where the sent email will be stored and whether it should
be digitally signed and/or encrypted.

<p>Below that, you see a list of "attachments". The mail you've just
entered before is also an attachment, but due to its special type
(it's plain text), it will be displayed as the normal message on
the receiver's side.

<p>At this point, you can add more attachments, pressing <tt/a/, you
can edit the recipient addresses, pressing <tt/t/ for the "To:" field,
<tt/c/ for the "Cc:" field, and <tt/b/ for the "Bcc: field. You can
also edit the subject the subject by simply pressing <tt/s/ or the
email message that you've entered before by pressing <tt/e/. You will
then again return to the editor. You can even edit the sender, by pressing
<tt/&lt;esc&gt;f/, but this shall only be used with caution.

<p>Alternatively, you can configure mutt-ng in a way that most of the
above settings can be edited using the editor. Therefore, you only
need to add the following to your configuration:

<verb>
set edit_headers
</verb>

<p>Once you have finished editing the body of your mail message, you are
returned to the <em/compose/ menu.  The following options are available:

<tscreen><verb>
a       attach-file             attach a file
A       attach-message          attach message(s) to the message
ESC k   attach-key              attach a PGP public key
d       edit-description        edit description on attachment
D       detach-file             detach a file
t       edit-to                 edit the To field
ESC f   edit-from               edit the From field
r       edit-reply-to           edit the Reply-To field
c       edit-cc                 edit the Cc field
b       edit-bcc                edit the Bcc field
y       send-message            send the message
s       edit-subject            edit the Subject
S       smime-menu              select S/MIME options
f       edit-fcc                specify an ``Fcc'' mailbox
p       pgp-menu                select PGP options
P       postpone-message        postpone this message until later
q       quit                    quit (abort) sending the message
w       write-fcc               write the message to a folder
i       ispell                  check spelling (if available on your system)
^F      forget-passphrase       wipe passphrase(s) from memory
</verb></tscreen>

<bf/Note:/ The attach-message function will prompt you for a folder to
attach messages from. You can now tag messages in that folder and they
will be attached to the message you are sending. Note that certain
operations like composing a new mail, replying, forwarding, etc. are
not permitted when you are in that folder. The %r in <ref
id="status_format" name="&dollar;status&lowbar;format"> will change to
a 'A' to indicate that you are in attach-message mode.

<!--}}}--> 

<sect1>Replying <!--{{{--> 

    <sect2>Simple Replies  <!--{{{--> 

    <p>When you want to reply to an email message, select it in the index
    menu and then press <tt/r/. Mutt-ng's behaviour is then similar to the 
    behaviour when you compose a message: first, you will be asked for
    the recipient, then for the subject, and then, mutt-ng will start
    the editor with the quote attribution and the quoted message. This
    can e.g. look like the example below.

    <verb>
On Mon, Mar 07, 2005 at 05:02:12PM +0100, Michael Svensson wrote:
&gt; Bill, can you please send last month's progress report to Mr. 
&gt; Morgan? We also urgently need the cost estimation for the new 
&gt; production server that we want to set up before our customer's 
&gt; project will go live.
    </verb>

    <p>You can start editing the email message. It is strongly
    recommended to put your answer <em/below/ the quoted text and to
    only quote what is really necessary and that you refer to. Putting
    your answer on top of the quoted message, is, although very
    widespread, very often not considered to be a polite way to answer
    emails.

    <p>The quote attribution is configurable, by default it is set to
    <verb>
set attribution = "On %d, %n wrote:"
    </verb>

    <p>It can also be set to something more compact, e.g.
    <verb>
set attribution = "attribution="* %n &lt;%a&gt; [%(%y-%m-%d %H:%M)]:"
    </verb>

    <p>The example above results in the following attribution:
    <verb>
* Michael Svensson &lt;svensson@foobar.com&gt; [05-03-06 17:02]:
&gt; Bill, can you please send last month's progress report to Mr. 
&gt; Morgan? We also urgently need the cost estimation for the new 
&gt; production server that we want to set up before our customer's 
&gt; project will go live.
    </verb>

    <p>Generally, try to keep your attribution short yet
    information-rich. It is <em/not/ the right place for witty quotes,
    long "attribution" novels or anything like that: the right place
    for such things is - if at all - the email signature at the very
    bottom of the message.

    <p>When you're done with writing your message, save and quit the
    editor. As before, you will return to the compose menu, which is
    used in the same way as before.

    <!--}}}--> 

    <sect2>Group Replies <!--{{{--> 

    <p>In the situation where a group of people uses email as a
    discussion, most of the emails will have one or more recipients,
    and probably several "Cc:" recipients. The group reply functionality
    ensures that when you press <tt/g/ instead of <tt/r/ to do a reply,
    each and every recipient that is contained in the original message
    will receive a copy of the message, either as normal recipient or
    as "Cc:" recipient.

    <!--}}}--> 

    <sect2>List Replies <!--{{{--> 

    <p>When you use mailing lists, it's generally better to send your
    reply to a message only to the list instead of the list and the
    original author. To make this easy to use, mutt-ng features list
    replies.

    <p>To do a list reply, simply press <tt/L/. If the email contains
    a <tt/Mail-Followup-To:/ header, its value will be used as reply
    address. Otherwise, mutt-ng searches through all mail addresses in
    the original message and tries to match them a list of regular
    expressions which can be specified using the <tt/lists/ command. 
    If any of the regular expression matches, a mailing
    list address has been found, and it will be used as reply address.

    <verb>
lists linuxevent@luga\.at vuln-dev@ mutt-ng-users@
    </verb>

    <p>Nowadays, most mailing list software like GNU Mailman adds a
    <tt/Mail-Followup-To:/ header to their emails anyway, so setting
    <tt/lists/ is hardly ever necessary in practice.

    <!--}}}--> 

<!--}}}--> 

<sect1>Editing the message header <!--{{{--> 
<p>
When editing the header of your outgoing message, there are a couple of
special features available.

If you specify<newline>
<tt/Fcc:/ <em/filename/<newline>
Mutt-ng will pick up <em/filename/
just as if you had used the <em/edit-fcc/ function in the <em/compose/ menu.

You can also attach files to your message by specifying<newline>
<tt/Attach:/ <em/filename/  &lsqb; <em/description/ &rsqb;<newline>
where <em/filename/ is the file to attach and <em/description/ is an
optional string to use as the description of the attached file.

When replying to messages, if you remove the <em/In-Reply-To:/ field from
the header field, Mutt-ng will not generate a <em/References:/ field, which
allows you to create a new message thread.

Also see <ref id="edit_headers" name="edit&lowbar;headers">.

<!--}}}--> 

<sect1>Using Mutt-ng with PGP <!--{{{--> 

<p>
If you want to use PGP, you can specify 

<tt/Pgp:/ &lsqb; <tt/E/ | <tt/S/ | <tt/S/<em/&lt;id&gt;/ &rsqb; <newline>

``E'' encrypts, ``S'' signs and
``S&lt;id&gt;'' signs with the given key, setting <ref
id="pgp_sign_as" name="&dollar;pgp&lowbar;sign&lowbar;as"> permanently.

If you have told mutt to PGP encrypt a message, it will guide you
through a key selection process when you try to send the message.
Mutt-ng will not ask you any questions about keys which have a
certified user ID matching one of the message recipients' mail
addresses.  However, there may be situations in which there are
several keys, weakly certified user ID fields, or where no matching
keys can be found.

In these cases, you are dropped into a menu with a list of keys from
which you can select one.  When you quit this menu, or mutt can't
find any matching keys, you are prompted for a user ID.  You can, as
usually, abort this prompt using <tt/^G/.  When you do so, mutt will
return to the compose screen.

Once you have successfully finished the key selection, the message
will be encrypted using the selected public keys, and sent out.

Most fields of the entries in the key selection menu (see also <ref
id="pgp_entry_format" name="&dollar;pgp&lowbar;entry&lowbar;format">) 
have obvious meanings.  But some explanations on the capabilities, flags, 
and validity fields are in order.

The flags sequence (&percnt;f) will expand to one of the following flags:
<tscreen><verb>
R            The key has been revoked and can't be used.
X            The key is expired and can't be used.
d            You have marked the key as disabled.
c            There are unknown critical self-signature 
             packets.
</verb></tscreen>

The capabilities field (&percnt;c) expands to a two-character sequence
representing a key's capabilities.  The first character gives
the key's encryption capabilities: A minus sign (<bf/-/) means 
that the key cannot be used for encryption.  A dot (<bf/./) means that
it's marked as a signature key in one of the user IDs, but may 
also be used for encryption.  The letter <bf/e/ indicates that 
this key can be used for encryption.
 
The second character indicates the key's signing capabilities.  Once 
again, a ``<bf/-/'' implies ``not for signing'', ``<bf/./'' implies
that the key is marked as an encryption key in one of the user-ids, and
``<bf/s/'' denotes a key which can be used for signing.

Finally, the validity field (%t) indicates how well-certified a user-id
is.  A question mark (<bf/?/) indicates undefined validity, a minus 
character (<bf/-/) marks an untrusted association, a space character 
means a partially trusted association, and a plus character (<bf/+/) 
indicates complete validity.

<!--}}}--> 

<sect1>Sending anonymous messages via mixmaster <!--{{{--> 

<p>
You may also have configured mutt to co-operate with Mixmaster, an
anonymous remailer.  Mixmaster permits you to send your messages
anonymously using a chain of remailers. Mixmaster support in mutt is for 
mixmaster version 2.04 (beta 45 appears to be the latest) and 2.03. 
It does not support earlier versions or the later so-called version 3 betas, 
of which the latest appears to be called 2.9b23.

To use it, you'll have to obey certain restrictions.  Most
important, you cannot use the <tt/Cc/ and <tt/Bcc/ headers.  To tell
Mutt-ng to use mixmaster, you have to select a remailer chain, using
the mix function on the compose menu.  

The chain selection screen is divided into two parts.  In the
(larger) upper part, you get a list of remailers you may use.  In
the lower part, you see the currently selected chain of remailers.

You can navigate in the chain using the <tt/chain-prev/ and
<tt/chain-next/ functions, which are by default bound to the left
and right arrows and to the <tt/h/ and <tt/l/ keys (think vi
keyboard bindings).  To insert a remailer at the current chain
position, use the <tt/insert/ function.  To append a remailer behind
the current chain position, use <tt/select-entry/ or <tt/append/.
You can also delete entries from the chain, using the corresponding
function.  Finally, to abandon your changes, leave the menu, or
<tt/accept/ them pressing (by default) the <tt/Return/ key.

Note that different remailers do have different capabilities,
indicated in the &percnt;c entry of the remailer menu lines (see
<ref id="mix_entry_format"
name="&dollar;mix&lowbar;entry&lowbar;format">).  Most important is
the ``middleman'' capability, indicated by a capital ``M'': This
means that the remailer in question cannot be used as the final
element of a chain, but will only forward messages to other
mixmaster remailers.  For details on the other capabilities, please
have a look at the mixmaster documentation.

<!--}}}--> 

<!--}}}--> 

<sect>Forwarding and Bouncing Mail<label id="forwarding_mail"> <!--{{{--> 

<p>Often, it is necessary to forward mails to other people.
Therefore, mutt-ng supports forwarding messages in two different
ways.

<p>The first one is regular forwarding, as you probably know it from
other mail clients. You simply press <tt/f/, enter the recipient
email address, the subject of the forwarded email, and then you can
edit the message to be forwarded in the editor. The forwarded
message is separated from the rest of the message via the two
following markers:

<verb>
----- Forwarded message from Lucas User <luser@example.com> -----

From: Lucas User <luser@example.com>
Date: Thu, 02 Dec 2004 03:08:34 +0100
To: Michael Random <mrandom@example.com>
Subject: Re: blackmail

Pay me EUR 50,000.- cash or your favorite stuffed animal will die
a horrible death.


----- End forwarded message -----</verb>

<p>When you're done with editing the mail, save and quit the editor,
and you will return to the compose menu, the same menu you also
encounter when composing or replying to mails.

<p>The second mode of forwarding emails with mutt-ng is the
so-called <em/bouncing/: when you bounce an email to another
address, it will be sent in practically the same format you send it
(except for headers that are created during transporting the
message). To bounce a message, press <tt/b/ and enter the recipient
email address. By default, you are then asked whether you really
want to bounce the message to the specified recipient. If you answer
with yes, the message will then be bounced.

<p>To the recipient, the bounced email will look as if he got it
like a regular email where he was <tt/Bcc:/ recipient. The only
possibility to find out whether it was a bounced email is to
carefully study the email headers and to find out which host really
sent the email.

<!--}}}--> 

<sect>Postponing Mail<label id="postponing_mail"> <!--{{{--> 
<p>

At times it is desirable to delay sending a message that you have
already begun to compose.  When the <em/postpone-message/ function is
used in the <em/compose/ menu, the body of your message and attachments
are stored in the mailbox specified by the <ref id="postponed"
name="&dollar;postponed"> variable.  This means that you can recall the
message even if you exit Mutt-ng and then restart it at a later time.

Once a message is postponed, there are several ways to resume it.  From the
command line you can use the ``-p'' option, or if you <em/compose/ a new
message from the <em/index/ or <em/pager/ you will be prompted if postponed
messages exist.  If multiple messages are currently postponed, the
<em/postponed/ menu will pop up and you can select which message you would
like to resume.

<bf/Note:/ If you postpone a reply to a message, the reply setting of
the message is only updated when you actually finish the message and
send it.  Also, you must be in the same folder with the message you
replied to for the status of the message to be updated.

See also the <ref id="postpone" name="&dollar;postpone"> quad-option.

<!--}}}--> 

<!--}}}--> 

<chapt>Configuration <!--{{{--> 

<sect>Locations of Configuration Files <!--{{{--> 
<p>While the default configuration (or ``preferences'') make Mutt-ng usable right out
of the box, it is often desirable to tailor Mutt-ng to suit your own tastes. When
Mutt-ng is first invoked, it will attempt to read the ``system'' configuration
file (defaults set by your local system administrator), unless the ``-n'' <ref
id="commandline" name="command line"> option is specified.  This file is
typically <tt>/usr/local/share/muttng/Muttngrc</tt> or <tt>/etc/Muttngrc</tt>,
Mutt-ng users will find this file in <tt>/usr/local/share/muttng/Muttrc</tt> or
<tt>/etc/Muttngrc</tt>. Mutt will next look for a file named <tt>.muttrc</tt>
in your home directory, Mutt-ng will look for <tt>.muttngrc</tt>.  If this file
does not exist and your home directory has a subdirectory named <tt/.mutt/,
mutt try to load a file named <tt>.muttng/muttngrc</tt>. 

<tt>.muttrc</tt> (or <tt>.muttngrc</tt> for Mutt-ng) is the file where you will
usually place your <ref id="commands" name="commands"> to configure Mutt-ng.

<!--}}}--> 

<sect>Basic Syntax of Initialization Files<label id="muttrc-syntax"> <!--{{{--> 
<p>

An initialization file consists of a series of <ref id="commands"
name="commands">.  Each line of the file may contain one or more commands.
When multiple commands are used, they must be separated by a semicolon (;).
<tscreen><verb>
set realname='Mutt-ng user' ; ignore x-
</verb></tscreen>
The hash mark, or pound sign
(``&num;''), is used as a ``comment'' character. You can use it to
annotate your initialization file. All text after the comment character
to the end of the line is ignored. For example,

<tscreen><verb>
my_hdr X-Disclaimer: Why are you listening to me? &num; This is a comment
</verb></tscreen>

Single quotes (') and double quotes (&dquot;) can be used to quote strings
which contain spaces or other special characters.  The difference between
the two types of quotes is similar to that of many popular shell programs,
namely that a single quote is used to specify a literal string (one that is
not interpreted for shell variables or quoting with a backslash &lsqb;see
next paragraph&rsqb;), while double quotes indicate a string for which
should be evaluated.  For example, backtics are evaluated inside of double
quotes, but <bf/not/ for single quotes.

&bsol; quotes the next character, just as in shells such as bash and zsh.
For example, if want to put quotes ``&dquot;'' inside of a string, you can use
``&bsol;'' to force the next character to be a literal instead of interpreted
character.
<tscreen><verb>
set realname="Michael \"MuttDude\" Elkins"
</verb></tscreen>

``&bsol;&bsol;'' means to insert a literal ``&bsol;'' into the line.
``&bsol;n'' and ``&bsol;r'' have their usual C meanings of linefeed and
carriage-return, respectively.

A &bsol; at the end of a line can be used to split commands over
multiple lines, provided that the split points don't appear in the
middle of command names.

Please note that, unlike the various shells, mutt-ng interprets a ``&bsol;''
at the end of a line also in comments. This allows you to disable a command
split over multiple lines with only one ``&num;''.

<tscreen><verb>
# folder-hook . \
  set realname="Michael \"MuttDude\" Elkins"
</verb></tscreen>

When testing your config files, beware the following caveat. The backslash
at the end of the commented line extends the current line with the next line
- then referred to as a ``continuation line''.  As the first line is
commented with a hash (&num;) all following continuation lines are also
part of a comment and therefore are ignored, too. So take care of comments
when continuation lines are involved within your setup files!

Abstract example:
 
<tscreen><verb>
line1\
line2a # line2b\
line3\
line4
line5
</verb></tscreen>

line1 ``continues'' until line4. however, the part after the &num; is a
comment which includes line3 and line4. line5 is a new line of its own and
thus is interpreted again.

The commands understood by mutt are explained in the next paragraphs.
For a complete list, see the <ref id="commands" name="command reference">.

<!--}}}--> 

<sect>Expansion within variables <!--{{{--> 

  <p>Besides just assign static content to variables, there's plenty of
  ways of adding external and more or less dynamic content.

  <sect1>Commands' Output 

    <p>It is possible to substitute the output of a Unix command in an
    initialization file.  This is accomplished by enclosing the command
    in backquotes (``) as in, for example:

<tscreen><verb>
my_hdr X-Operating-System: `uname -a`
</verb></tscreen>

    <p>The output of the Unix command ``uname -a'' will be substituted
    before the line is parsed. Note that since initialization files are
    line oriented, only the first line of output from the Unix command
    will be substituted.

  <sect1>Environment Variables 

    <p>UNIX environments can be accessed like the way it is done in
    shells like sh and bash: Prepend the name of the environment by a
    ``&dollar;'' sign. For example,

<tscreen><verb>
set record=+sent_on_$HOSTNAME
</verb></tscreen>

    <p>sets the <ref id="record" name="&dollar;record"> variable to the
    string <em/+sent_on_/ and appends the value of the evironment
    variable <tt>&dollar;HOSTNAME</tt>.

    <p><bf/Note:/ There will be no warning if an environment variable
    is not defined. The result will of the expansion will then be empty.

  <sect1>Configuration Variables 

    <p>As for environment variables, the values of all configuration
    variables as string can be used in the same way, too. For example,

<tscreen><verb>
set imap_home_namespace = $folder
</verb></tscreen>

    <p>would set the value of <ref id="imap_home_namespace"
    name="&dollar;imap&lowbar;home&lowbar;namespace"> to the value to
    which <ref id="folder" name="&dollar;folder"> is <em/currently/ set
    to.

    <p><bf/Note:/ There're no logical links established in such cases so
    that the the value for <ref id="imap_home_namespace"
    name="&dollar;imap&lowbar;home&lowbar;namespace"> won't change even
    if <ref id="folder" name="&dollar;folder"> gets changed.

    <p><bf/Note:/ There will be no warning if a configuration variable
    is not defined or is empty. The result will of the expansion will
    then be empty.

  <sect1>Self-Defined Variables 

    <p>Mutt-ng flexibly allows users to define their own variables. To
    avoid conflicts with the standard set and to prevent misleading
    error messages, there's a reserved namespace for them: all
    user-defined variables must be prefixed with <tt/user_/ and can be
    used just like any ordinary configuration or environment
    variable.

    <p>For example, to view the manual, users can either define two
    macros like the following

<tscreen><verb>
macro generic &lt;F1&gt; "!less -r /path/to/manual" "Show manual"
macro pager &lt;F1&gt; "!less -r /path/to/manual" "Show manual"
</verb></tscreen>

    <p>for <tt/generic/, <tt/pager/ and <tt/index/. The alternative is to
    define a custom variable like so:

<tscreen><verb>
set user_manualcmd = "!less -r /path/to_manual"
macro generic &lt;F1&gt; "$user_manualcmd&lt;enter&gt;" "Show manual"
macro pager &lt;F1&gt; "$user_manualcmd&lt;enter&gt;" "Show manual"
macro index &lt;F1&gt; "$user_manualcmd&lt;enter&gt;" "Show manual"
</verb></tscreen>

    <p>to re-use the command sequence as in:

<tscreen><verb>
macro index &lt;F2&gt; "$user_manualcmd | grep '\^[ ]\\+~. '" "Show Patterns"
</verb></tscreen>

    <p>Using this feature, arbitrary sequences can be defined once and
    recalled and reused where necessary. More advanced scenarios could
    include to save a variable's value at the beginning of macro
    sequence and restore it at end.

    <p>When the variable is first defined, the first value it gets
    assigned is also the initial value to which it can be reset using
    the <tt/reset/ command.

    <p>The complete removal is done via the <tt/unset/ keyword.

    <p>After the following sequence:

<tscreen><verb>
set user_foo = 42
set user_foo = 666
</verb></tscreen>

    <p>the variable <tt>$user_foo</tt> has a current value of 666 and an
    initial of 42. The query

<tscreen><verb>
set ?user_foo
</verb></tscreen>

    <p>will show 666. After doing the reset via

<tscreen><verb>
reset user_foo
</verb></tscreen>

    <p>a following query will give 42 as the result. After unsetting it
    via

<tscreen><verb>
unset user_foo
</verb></tscreen>

    <p>any query or operation (except the noted expansion within other
    statements) will lead to an error message.

  <sect1>Pre-Defined Variables 

    <p>In order to allow users to share one setup over a number of
    different machines without having to change its contents, there's a
    number of pre-defined variables. These are prefixed with
    <tt/muttng_/ and are read-only, i.e. they cannot be set, unset or
    reset. The reference chapter lists all available variables.

    <p><em> Please consult the local copy of your manual for their
    values as they may differ from different manual sources.</em> Where
    the manual is installed in can be queried (already using such a
    variable) by running:

<tscreen><verb>
muttng -Q muttng_docdir
</verb></tscreen>

    <p>To extend the example for viewing the manual via self-defined
    variables, it can be made more readable and more portable by
    changing the real path in:

<tscreen><verb>
set user_manualcmd = '!less -r /path/to_manual'
</verb></tscreen>

    <p>to:

<tscreen><verb>
set user_manualcmd = "!less -r $muttng_docdir/manual.txt"
</verb></tscreen>

    <p>which works everywhere if a manual is installed.

    <p>Please note that by the type of quoting, muttng determines when
    to expand these values: when it finds double quotes, the value will
    be expanded during reading the setup files but when it finds single
    quotes, it'll expand it at runtime as needed.

    <p>For example, the statement

<tscreen><verb>
folder-hook . "set user_current_folder = $muttng_folder_name"
</verb></tscreen>

    <p>will be already be translated to the following when reading the
    startup files:

<tscreen><verb>
folder-hook . "set user_current_folder = some_folder"
</verb></tscreen>

    <p>with <tt/some_folder/ being the name of the first folder muttng
    opens. On the contrary,

<tscreen><verb>
folder-hook . 'set user_current_folder = $muttng_folder_name'
</verb></tscreen>

    <p>will be executed at runtime because of the single quotes so that
    <tt/user_current_folder/ will always have the value of the currently
    opened folder.

    <p>A more practical example is:

<tscreen><verb>
folder-hook . 'source ~/.mutt/score-$muttng_folder_name'
</verb></tscreen>

    <p>which can be used to source files containing score commands
    depending on the folder the user enters.

  <sect1>Type Conversions 

    <p>A note about variable's types during conversion: internally
    values are stored in internal types but for any dump/query or set
    operation they're converted to and from string. That means that
    there's no need to worry about types when referencing any variable.
    As an example, the following can be used without harm (besides
    makeing muttng very likely behave strange):

<tscreen><verb>
set read_inc = 100
set folder = $read_inc
set read_inc = $folder
set user_magic_number = 42
set folder = $user_magic_number
</verb></tscreen>

<!--}}}-->

<sect>Defining/Using aliases<label id="alias"> <!--{{{--> 
<p>

Usage: <tt/alias/ <em/key/ <em/address/ &lsqb; , <em/address/, ... &rsqb;

It's usually very cumbersome to remember or type out the address of someone
you are communicating with.  Mutt-ng allows you to create ``aliases'' which map
a short string to a full address.

<bf/Note:/ if you want to create an alias for a group (by specifying more than
one address), you <bf/must/ separate the addresses with a comma (``,'').

To remove an alias or aliases (``*'' means all aliases):

<tt/unalias/ &lsqb; * | <em/key/ <em/.../ &rsqb;

<tscreen><verb>
alias muttdude me@cs.hmc.edu (Michael Elkins)
alias theguys manny, moe, jack
</verb></tscreen>

Unlike other mailers, Mutt-ng doesn't require aliases to be defined
in a special file.  The <tt/alias/ command can appear anywhere in
a configuration file, as long as this file is <ref id="source"
name="sourced">.  Consequently, you can have multiple alias files, or
you can have all aliases defined in your muttrc.

On the other hand, the <ref id="create-alias" name="create-alias">
function can use only one file, the one pointed to by the <ref
id="alias_file" name="&dollar;alias&lowbar;file"> variable (which is
<tt>&tilde;/.muttrc</tt> by default). This file is not special either,
in the sense that Mutt-ng will happily append aliases to any file, but in
order for the new aliases to take effect you need to explicitly <ref
id="source" name="source"> this file too.

For example:

<tscreen><verb>
source /usr/local/share/Mutt-ng.aliases
source ~/.mail_aliases
set alias_file=~/.mail_aliases
</verb></tscreen>

To use aliases, you merely use the alias at any place in mutt where mutt
prompts for addresses, such as the <em/To:/ or <em/Cc:/ prompt.  You can
also enter aliases in your editor at the appropriate headers if you have the
<ref id="edit_headers" name="&dollar;edit&lowbar;headers"> variable set.

In addition, at the various address prompts, you can use the tab character
to expand a partial alias to the full alias.  If there are multiple matches,
mutt will bring up a menu with the matching aliases.  In order to be
presented with the full list of aliases, you must hit tab with out a partial
alias, such as at the beginning of the prompt or after a comma denoting
multiple addresses.

In the alias menu, you can select as many aliases as you want with the
<em/select-entry/ key (default: RET), and use the <em/exit/ key
(default: q) to return to the address prompt.

<!--}}}--> 

<sect>Changing the default key bindings<label id="bind"> <!--{{{--> 
<p>
Usage: <tt/bind/ <em/map/ <em/key/ <em/function/

This command allows you to change the default key bindings (operation
invoked when pressing a key).

<em/map/ specifies in which menu the binding belongs.  Multiple maps may
be specified by separating them with commas (no additional whitespace is
allowed). The currently defined maps are:

<label id="maps">
<descrip>
<tag/generic/
This is not a real menu, but is used as a fallback for all of the other
menus except for the pager and editor modes.  If a key is not defined in
another menu, Mutt-ng will look for a binding to use in this menu.  This allows
you to bind a key to a certain function in multiple menus instead of having
multiple bind statements to accomplish the same task.
<tag/alias/
The alias menu is the list of your personal aliases as defined in your
muttrc.  It is the mapping from a short alias name to the full email
address(es) of the recipient(s).
<tag/attach/
The attachment menu is used to access the attachments on received messages.
<tag/browser/
The browser is used for both browsing the local directory structure, and for
listing all of your incoming mailboxes.
<tag/editor/
The editor is the line-based editor the user enters text data.
<tag/index/
The index is the list of messages contained in a mailbox.
<tag/compose/
The compose menu is the screen used when sending a new message.
<tag/pager/
The pager is the mode used to display message/attachment data, and help
listings.
<tag/pgp/
The pgp menu is used to select the OpenPGP keys used for encrypting outgoing
messages.
<tag/postpone/
The postpone menu is similar to the index menu, except is used when
recalling a message the user was composing, but saved until later.
</descrip>

<em/key/ is the key (or key sequence) you wish to bind.  To specify a
control character, use the sequence <em/&bsol;Cx/, where <em/x/ is the
letter of the control character (for example, to specify control-A use
``&bsol;Ca'').  Note that the case of <em/x/ as well as <em/&bsol;C/ is
ignored, so that <em/&bsol;CA/, <em/&bsol;Ca/, <em/&bsol;cA/ and <em/&bsol;ca/ are all
equivalent.  An alternative form is to specify the key as a three digit
octal number prefixed with a ``&bsol;'' (for example <em/&bsol;177/ is
equivalent to <em/&bsol;c?/).

In addition, <em/key/ may consist of:

<tscreen><verb>
\t              tab
<tab>           tab
<backtab>       backtab / shift-tab
\r              carriage return
\n              newline
\e              escape
<esc>           escape
<up>            up arrow
<down>          down arrow
<left>          left arrow
<right>         right arrow
<pageup>        Page Up
<pagedown>      Page Down
<backspace>     Backspace
<delete>        Delete
<insert>        Insert
<enter>         Enter
<return>        Return
<home>          Home
<end>           End
<space>         Space bar
<f1>            function key 1
<f10>           function key 10
</verb></tscreen>

<em/key/ does not need to be enclosed in quotes unless it contains a
space (`` '').

<em/function/ specifies which action to take when <em/key/ is pressed.
For a complete list of functions, see the <ref id="functions"
name="reference">.  The special function <tt/noop/ unbinds the specified key
sequence.

<!--}}}--> 

<sect>Defining aliases for character sets <label id="charset-hook"> <!--{{{--> 
<p>
Usage: <tt/charset-hook/ <em/alias/ <em/charset/<newline>
Usage: <tt/iconv-hook/ <em/charset/ <em/local-charset/

The <tt/charset-hook/ command defines an alias for a character set.
This is useful to properly display messages which are tagged with a
character set name not known to mutt.

The <tt/iconv-hook/ command defines a system-specific name for a
character set.  This is helpful when your systems character
conversion library insists on using strange, system-specific names
for character sets.

<!--}}}--> 

<sect>Setting variables based upon mailbox<label id="folder-hook"> <!--{{{--> 
<p>
Usage: <tt/folder-hook/ &lsqb;!&rsqb;<em/regexp/ <em/command/

It is often desirable to change settings based on which mailbox you are
reading.  The folder-hook command provides a method by which you can execute
any configuration command.  <em/regexp/ is a regular expression specifying
in which mailboxes to execute <em/command/ before loading.  If a mailbox
matches multiple folder-hook's, they are executed in the order given in the
muttrc.

<bf/Note:/ if you use the ``!'' shortcut for <ref id="spoolfile"
name="&dollar;spoolfile"> at the beginning of the pattern, you must place it
inside of double or single quotes in order to distinguish it from the
logical <em/not/ operator for the expression.

Note that the settings are <em/not/ restored when you leave the mailbox.
For example, a command action to perform is to change the sorting method
based upon the mailbox being read:

<tscreen><verb>
folder-hook mutt set sort=threads
</verb></tscreen>

However, the sorting method is not restored to its previous value when
reading a different mailbox.  To specify a <em/default/ command, use the
pattern ``.'':

<p>
<tscreen><verb>
folder-hook . set sort=date-sent
</verb></tscreen>

<!--}}}--> 

<sect>Keyboard macros<label id="macro"> <!--{{{--> 
<p>
Usage: <tt/macro/ <em/menu/ <em/key/ <em/sequence/ &lsqb; <em/description/ &rsqb;

Macros are useful when you would like a single key to perform a series of
actions.  When you press <em/key/ in menu <em/menu/, Mutt-ng will behave as if
you had typed <em/sequence/.  So if you have a common sequence of commands
you type, you can create a macro to execute those commands with a single
key.

<em/menu/ is the <ref id="maps" name="map"> which the macro will be bound.
Multiple maps may be specified by separating multiple menu arguments by
commas. Whitespace may not be used in between the menu arguments and the
commas separating them.

<em/key/ and <em/sequence/ are expanded by the same rules as the <ref
id="bind" name="key bindings">.  There are some additions however.  The
first is that control characters in <em/sequence/ can also be specified
as <em/&circ;x/.  In order to get a caret (`&circ;'') you need to use
<em/&circ;&circ;/.  Secondly, to specify a certain key such as <em/up/
or to invoke a function directly, you can use the format
<em/&lt;key name&gt;/ and <em/&lt;function name&gt;/.  For a listing of key
names see the section on <ref id="bind" name="key bindings">.  Functions
are listed in the <ref id="functions" name="function reference">.

The advantage with using function names directly is that the macros will
work regardless of the current key bindings, so they are not dependent on
the user having particular key definitions.  This makes them more robust
and portable, and also facilitates defining of macros in files used by more
than one user (eg. the system Muttngrc).

Optionally you can specify a descriptive text after <em/sequence/,
which is shown in the help screens.

<bf/Note:/ Macro definitions (if any) listed in the help screen(s), are
silently truncated at the screen width, and are not wrapped.   

<!--}}}--> 

<sect>Using color and mono video attributes<label id="color"> <!--{{{--> 
<p>
Usage: <tt/color/ <em/object/ <em/foreground/ <em/background/ &lsqb; <em/regexp/ &rsqb;<newline>
Usage: <tt/color/ index <em/foreground/ <em/background/ <em/pattern/<newline>
Usage: <tt/uncolor/ index <em/pattern/ &lsqb; <em/pattern/ ...  &rsqb;<newline>

If your terminal supports color, you can spice up Mutt-ng by creating your own
color scheme.  To define the color of an object (type of information), you
must specify both a foreground color <bf/and/ a background color (it is not
possible to only specify one or the other).

<em/object/ can be one of:

<itemize>
<item>attachment
<item>body (match <em/regexp/ in the body of messages)
<item>bold (highlighting bold patterns in the body of messages)
<item>error (error messages printed by Mutt-ng)
<item>header (match <em/regexp/ in the message header)
<item>hdrdefault (default color of the message header in the pager)
<item>index (match <em/pattern/ in the message index)
<item>indicator (arrow or bar used to indicate the current item in a menu)
<item>markers (the ``+'' markers at the beginning of wrapped lines in the pager)
<item>message (informational messages)
<item>normal
<item>quoted (text matching <ref id="quote_regexp"
name="&dollar;quote&lowbar;regexp"> in the body of a message)
<item>quoted1, quoted2, ..., quoted<bf/N/ (higher levels of quoting)
<item>search (highlighting of words in the pager)
<item>signature
<item>status (mode lines used to display info about the mailbox or message)
<item>tilde (the ``&tilde;'' used to pad blank lines in the pager)
<item>tree (thread tree drawn in the message index and attachment menu)
<item>underline (highlighting underlined patterns in the body of messages)
</itemize>

<em/foreground/ and <em/background/ can be one of the following:

<itemize>
<item>white
<item>black
<item>green
<item>magenta
<item>blue
<item>cyan
<item>yellow
<item>red
<item>default
<item>color<em/x/
</itemize>

<em/foreground/ can optionally be prefixed with the keyword <tt/bright/ to make
the foreground color boldfaced (e.g., <tt/brightred/).

If your terminal supports it, the special keyword <em/default/ can be
used as a transparent color.  The value <em/brightdefault/ is also valid.
If Mutt-ng is linked against the <em/S-Lang/ library, you also need to set
the <em/COLORFGBG/ environment variable to the default colors of your
terminal for this to work; for example (for Bourne-like shells):

<tscreen><verb>
set COLORFGBG="green;black"
export COLORFGBG
</verb></tscreen>

<bf/Note:/ The <em/S-Lang/ library requires you to use the <em/lightgray/
and <em/brown/ keywords instead of <em/white/ and <em/yellow/ when
setting this variable.

<bf/Note:/ The uncolor command can be applied to the index object only.  It
removes entries from the list. You <bf/must/ specify the same pattern
specified in the color command for it to be removed.  The pattern ``*'' is
a special token which means to clear the color index list of all entries.

Mutt-ng also recognizes the keywords <em/color0/, <em/color1/, &hellip;,
<em/color/<bf/N-1/ (<bf/N/ being the number of colors supported
by your terminal).  This is useful when you remap the colors for your
display (for example by changing the color associated with <em/color2/
for your xterm), since color names may then lose their normal meaning.

If your terminal does not support color, it is still possible change the video
attributes through the use of the ``mono'' command:

Usage: <tt/mono/ <em/&lt;object&gt; &lt;attribute&gt;/ &lsqb; <em/regexp/ &rsqb;<newline>
Usage: <tt/mono/ index <em/attribute/ <em/pattern/<newline>
Usage: <tt/unmono/ index <em/pattern/ &lsqb; <em/pattern/ ...  &rsqb;<newline>

where <em/attribute/ is one of the following:

<itemize>
<item>none
<item>bold
<item>underline
<item>reverse
<item>standout
</itemize>

<!--}}}--> 

<sect>Ignoring (weeding) unwanted message headers<label id="ignore"> <!--{{{--> 
<p>
Usage: <tt/&lsqb;un&rsqb;ignore/ <em/pattern/ &lsqb; <em/pattern/ ... &rsqb;

Messages often have many header fields added by automatic processing systems,
or which may not seem useful to display on the screen.  This command allows
you to specify header fields which you don't normally want to see.

You do not need to specify the full header field name.  For example,
``ignore content-'' will ignore all header fields that begin with the pattern
``content-''. ``ignore *'' will ignore all headers.

To remove a previously added token from the list, use the ``unignore'' command.
The ``unignore'' command will make Mutt-ng display headers with the given pattern.
For example, if you do ``ignore x-'' it is possible to ``unignore x-mailer''.

``unignore *'' will remove all tokens from the ignore list.

For example:
<tscreen><verb>
# Sven's draconian header weeding
ignore *
unignore from date subject to cc
unignore organization organisation x-mailer: x-newsreader: x-mailing-list:
unignore posted-to:
</verb></tscreen>

<!--}}}--> 

<sect>Alternative addresses<label id="alternates"> <!--{{{--> 
<p>
Usage: <tt/&lsqb;un&rsqb;alternates/ <em/regexp/ &lsqb; <em/regexp/ ... &rsqb;<newline>

With various functions, mutt will treat messages differently,
depending on whether you sent them or whether you received them from
someone else.  For instance, when replying to a message that you
sent to a different party, mutt will automatically suggest to send
the response to the original message's recipients -- responding to
yourself won't make much sense in many cases.  (See <ref
id="reply_to" name="&dollar;reply&lowbar;to">.)

Many users receive e-mail under a number of different addresses. To
fully use mutt's features here, the program must be able to
recognize what e-mail addresses you receive mail under. That's the
purpose of the <tt/alternates/ command: It takes a list of regular
expressions, each of which can identify an address under which you
receive e-mail.

The <tt/unalternates/ command can be used to write exceptions to
<tt/alternates/ patterns. If an address matches something in an
<tt/alternates/ command, but you nonetheless do not think it is
from you, you can list a more precise pattern under an <tt/unalternates/
command.

To remove a regular expression from the <tt/alternates/ list, use the
<tt/unalternates/ command with exactly the same <em/regexp/.
Likewise, if the <em/regexp/ for a <tt/alternates/ command matches
an entry on the <tt/unalternates/ list, that <tt/unalternates/
entry will be removed. If the <em/regexp/ for <tt/unalternates/
is ``*'', <em/all entries/ on <tt/alternates/ will be removed.

<!--}}}--> 

<sect>Format = Flowed <!--{{{--> 

  <sect1>Introduction <!--{{{--> 

    <p>Mutt-ng contains support for so-called <tt/format=flowed/ messages.
    In the beginning of email, each message had a fixed line width, and
    it was enough for displaying them on fixed-size terminals. But times
    changed, and nowadays hardly anybody still uses fixed-size terminals:
    more people nowaydays use graphical user interfaces, with dynamically
    resizable windows. This led to the demand of a new email format that
    makes it possible for the email client to make the email look nice
    in a resizable window without breaking quoting levels and creating
    an incompatible email format that can also be displayed nicely on
    old fixed-size terminals.

    <p>For introductory information on <tt/format=flowed/ messages, see
    <htmlurl url="http://www.joeclark.org/ffaq.html"
    name="&lt;http://www.joeclark.org/ffaq.html&gt;">.

  <!--}}}-->

  <sect1>Receiving: Display Setup <!--{{{--> 

    <p>When you receive emails that are marked as <tt/format=flowed/
    messages, and is formatted correctly, mutt-ng will try to reformat
    the message to optimally fit on your terminal. If you want a fixed
    margin on the right side of your terminal, you can set the
    following:

    <verb>
    set wrapmargin = 10
    </verb>

    <p>The code above makes the line break 10 columns before the right
    side of the terminal.

    <p>If your terminal is so wide that the lines are embarrassingly long,
    you can also set a maximum line length:

    <verb>
    set max_line_length = 120
    </verb>

    <p>The example above will give you lines not longer than 120
    characters.

    <p>When you view at <tt/format=flowed/ messages, you will often see
    the quoting hierarchy like in the following example:

    <verb>
    &gt;Bill, can you please send last month's progress report to Mr. 
    &gt;Morgan? We also urgently need the cost estimation for the new 
    &gt;production server that we want to set up before our customer's 
    &gt;project will go live.
    </verb>

    <p>This obviously doesn't look very nice, and it makes it very
    hard to differentiate between text and quoting character. The
    solution is to configure mutt-ng to "stuff" the quoting:

    <verb>
    set stuff_quoted
    </verb>

    <p>This will lead to a nicer result that is easier to read:

    <verb>
    &gt; Bill, can you please send last month's progress report to Mr. 
    &gt; Morgan? We also urgently need the cost estimation for the new 
    &gt; production server that we want to set up before our customer's 
    &gt; project will go live.
    </verb>

  <!--}}}-->

  <sect1>Sending <!--{{{--> 

    <p>If you want mutt-ng to send emails with <tt/format=flowed/ set, you
    need to explicitly set it:

    <verb>
    set text_flowed
    </verb>

    <p>Additionally, you have to use an editor which supports writing
    <tt/format=flowed/-conforming emails. For vim, this is done by
    adding <tt/w/ to the formatoptions (see <tt/:h formatoptions/ and
    <tt/:h fo-table/) when writing emails.

    <p>Also note that <em/format=flowed/ knows about ``space-stuffing'',
    that is, when sending messages, some kinds of lines have to be
    indented with a single space on the sending side. On the receiving
    side, the first space (if any) is removed. As a consequence and in
    addition to the above simple setting, please keep this in mind when
    making manual formattings within the editor. Also note that mutt-ng
    currently violates the standard (RfC 3676) as it does not
    space-stuff lines starting with:

    <itemize>

      <item><tt/&gt;/ This is <em/not/ the quote character but a right
        angle used for other reasons

      <item><tt/From/ with a trailing space.

      <item>just a space for formatting reasons

    </itemize>

    Please make sure that you manually prepend a space to each of them.

  <!--}}}-->

  <sect1>Additional Notes <!--{{{-->

    <p> For completeness, the <ref id="delete_space"
    name="&dollar;delete&lowbar;space"> variable provides the mechanism
    to generate a <tt/DelSp=yes/ parameter on <em/outgoing/ messages.
    According to the standard, clients receiving a <tt/format=flowed/
    messages should delete the last space of a flowed line but still
    interpret the line as flowed. Because flowed lines usually contain
    only one space at the end, this parameter would make the receiving
    client concatenate the last word of the previous with the first of
    the current line <em/without/ a space. This makes ordinary text
    unreadable and is intended for languages rarely using spaces. So
    please use this setting only if you're sure what you're doing.

  <!--}}}-->

<!--}}}--> 

<sect>Mailing lists<label id="lists"> <!--{{{--> 
<p>
Usage: <tt/&lsqb;un&rsqb;lists/ <em/regexp/ &lsqb; <em/regexp/ ... &rsqb;<newline>
Usage: <tt/&lsqb;un&rsqb;subscribe/ <em/regexp/ &lsqb; <em/regexp/ ... &rsqb;

Mutt-ng has a few nice features for <ref id="using_lists" name="handling
mailing lists">.  In order to take advantage of them, you must
specify which addresses belong to mailing lists, and which mailing
lists you are subscribed to.  Once you have done this, the <ref
id="list-reply" name="list-reply"> function will work for all known lists.
Additionally, when you send a message to a subscribed list, mutt will
add a Mail-Followup-To header to tell other users' mail user agents
not to send copies of replies to your personal address.   Note that
the Mail-Followup-To header is a non-standard extension which is not
supported by all mail user agents.  Adding it is not bullet-proof against
receiving personal CCs of list messages.  Also note that the generation
of the Mail-Followup-To header is controlled by the <ref id="followup_to"
name="&dollar;followup&lowbar;to"> configuration variable.

More precisely, Mutt-ng maintains lists of patterns for the addresses
of known and subscribed mailing lists.  Every subscribed mailing
list is known. To mark a mailing list as known, use the ``lists''
command.  To mark it as subscribed, use ``subscribe''.

You can use regular expressions with both commands.  To mark all
messages sent to a specific bug report's address on mutt's bug
tracking system as list mail, for instance, you could say
``subscribe [0-9]*@bugs.guug.de''.  Often, it's sufficient to just
give a portion of the list's e-mail address.

Specify as much of the address as you need to to remove ambiguity.  For
example, if you've subscribed to the Mutt-ng mailing list, you will receive mail
addressed to <em/mutt-users@mutt.org/.  So, to tell Mutt-ng that this is a
mailing list, you could add ``lists mutt-users'' to your
initialization file.  To tell mutt that you are subscribed to it,
add ``subscribe mutt-users'' to your initialization file instead.
If you also happen to get mail from someone whose address is
<em/mutt-users@example.com/, you could use ``lists mutt-users@mutt&bsol;&bsol;.org'' 
or ``subscribe mutt-users@mutt&bsol;&bsol;.org'' to
match only mail from the actual list.

The ``unlists'' command is used to remove a token from the list of
known and subscribed mailing-lists. Use ``unlists *'' to remove all
tokens.

To remove a mailing list from the list of subscribed mailing lists,
but keep it on the list of known mailing lists, use ``unsubscribe''.

<!--}}}--> 

<sect>Using Multiple spool mailboxes<label id="mbox-hook"> <!--{{{--> 
<p>
Usage: <tt/mbox-hook/ &lsqb;!&rsqb;<em/pattern/ <em/mailbox/

This command is used to move read messages from a specified mailbox to a
different mailbox automatically when you quit or change folders.
<em/pattern/ is a regular expression specifying the mailbox to treat as a
``spool'' mailbox and <em/mailbox/ specifies where mail should be saved when
read.

Unlike some of the other <em/hook/ commands, only the <em/first/ matching
pattern is used (it is not possible to save read mail in more than a single
mailbox).

<!--}}}--> 

<sect>Defining mailboxes which receive mail<label id="mailboxes"> <!--{{{--> 
<p>
Usage: <tt/&lsqb;un&rsqb;mailboxes/ &lsqb;!&rsqb;<em/filename/ &lsqb; <em/filename/ ... &rsqb;

This command specifies folders which can receive mail and
which will be checked for new messages.  By default, the
main menu status bar displays how many of these folders have
new messages.
<p>
When changing folders, pressing <em/space/ will cycle
through folders with new mail.
<p>
Pressing TAB in the directory browser will bring up a menu showing the files
specified by the <tt/mailboxes/ command, and indicate which contain new
messages.  Mutt-ng will automatically enter this mode when invoked from the
command line with the <tt/-y/ option.

The ``unmailboxes'' command is used to remove a token from the list
of folders which receive mail. Use ``unmailboxes *'' to remove all
tokens.

<p>
<bf/Note:/ new mail is detected by comparing the last modification time to
the last access time.  Utilities like <tt/biff/ or <tt/frm/ or any other
program which accesses the mailbox might cause Mutt-ng to never detect new mail
for that mailbox if they do not properly reset the access time.  Backup
tools are another common reason for updated access times.
<p>

<bf/Note:/ the filenames in the <tt/mailboxes/ command are resolved when
the command is executed, so if these names contain <ref id="shortcuts"
name="shortcut characters"> (such as ``='' and ``!''), any variable
definition that affect these characters (like <ref id="folder"
name="&dollar;folder"> and <ref id="spoolfile" name="&dollar;spoolfile">)
should be executed before the <tt/mailboxes/ command.

<!--}}}--> 

<sect>User defined headers<label id="my_hdr"> <!--{{{--> 
<p>
Usage:<newline>
<tt/my_hdr/ <em/string/<newline>
<tt/unmy_hdr/ <em/field/ &lsqb; <em/field/ ... &rsqb;

The ``my&lowbar;hdr'' command allows you to create your own header
fields which will be added to every message you send.

For example, if you would like to add an ``Organization:'' header field to
all of your outgoing messages, you can put the command

<quote>
my_hdr Organization: A Really Big Company, Anytown, USA
</quote>

in your <tt/.muttrc/.

<bf/Note:/  space characters are <em/not/ allowed between the keyword and
the colon (``:'').  The standard for electronic mail (RFC822) says that
space is illegal there, so Mutt-ng enforces the rule.

If you would like to add a header field to a single message, you should
either set the <ref id="edit_headers" name="edit&lowbar;headers"> variable,
or use the <em/edit-headers/ function (default: ``E'') in the send-menu so
that you can edit the header of your message along with the body.

To remove user defined header fields, use the ``unmy&lowbar;hdr''
command.  You may specify an asterisk (``*'') to remove all header
fields, or the fields to remove.  For example, to remove all ``To'' and
``Cc'' header fields, you could use:

<quote>
unmy_hdr to cc
</quote>

<!--}}}--> 

<sect>Defining the order of headers when viewing messages<label id="hdr_order"> <!--{{{--> 
<p>
Usage: <tt/hdr&lowbar;order/ <em/header1/ <em/header2/ <em/header3/

With this command, you can specify an order in which mutt will attempt
to present headers to you when viewing messages.

``unhdr_order *'' will clear all previous headers from the order list,
thus removing the header order effects set by the system-wide startup
file.

<tscreen><verb>
hdr&lowbar;order From Date: From: To: Cc: Subject:
</verb></tscreen>

<!--}}}--> 

<sect>Specify default save filename<label id="save-hook"> <!--{{{--> 
<p>
Usage: <tt/save-hook/ &lsqb;!&rsqb;<em/pattern/ <em/filename/

This command is used to override the default filename used when saving
messages.  <em/filename/ will be used as the default filename if the message is
<em/From:/ an address matching <em/regexp/ or if you are the author and the
message is addressed <em/to:/ something matching <em/regexp/.

See <ref id="pattern_hook" name="Message Matching in Hooks"> for information on the exact format of <em/pattern/.

Examples:

<tscreen><verb>
save-hook me@(turing\\.)?cs\\.hmc\\.edu$ +elkins
save-hook aol\\.com$ +spam
</verb></tscreen>

Also see the <ref id="fcc-save-hook" name="fcc-save-hook"> command.

<!--}}}--> 

<sect>Specify default Fcc: mailbox when composing<label id="fcc-hook"> <!--{{{--> 
<p>
Usage: <tt/fcc-hook/ &lsqb;!&rsqb;<em/pattern/ <em/mailbox/

This command is used to save outgoing mail in a mailbox other than
<ref id="record" name="&dollar;record">.  Mutt-ng searches the initial list of
message recipients for the first matching <em/regexp/ and uses <em/mailbox/
as the default Fcc: mailbox.  If no match is found the message will be saved
to <ref id="record" name="&dollar;record"> mailbox.

See <ref id="pattern_hook" name="Message Matching in Hooks"> for information on the exact format of <em/pattern/.

Example: <tt/fcc-hook &lsqb;@.&rsqb;aol&bsol;&bsol;.com&dollar; +spammers/

The above will save a copy of all messages going to the aol.com domain to
the `+spammers' mailbox by default.  Also see the <ref id="fcc-save-hook" 
name="fcc-save-hook"> command.

<!--}}}--> 

<sect>Specify default save filename and default Fcc: mailbox at once<label id="fcc-save-hook"> <!--{{{--> 
<p>
Usage: <tt/fcc-save-hook/ &lsqb;!&rsqb;<em/pattern/ <em/mailbox/

This command is a shortcut, equivalent to doing both a <ref id="fcc-hook" name="fcc-hook">
and a <ref id="save-hook" name="save-hook"> with its arguments.

<!--}}}--> 

<sect>Change settings based upon message recipients<label id="send-hook"><label id="reply-hook"><label id="send2-hook"> <!--{{{--> 
<p>
Usage: <tt/reply-hook/ &lsqb;!&rsqb;<em/pattern/ <em/command/<newline>
Usage: <tt/send-hook/ &lsqb;!&rsqb;<em/pattern/ <em/command/<newline>
Usage: <tt/send2-hook/ &lsqb;!&rsqb;<em/pattern/ <em/command/

These commands can be used to execute arbitrary configuration commands based
upon recipients of the message.  <em/pattern/ is a regular expression
matching the desired address.  <em/command/ is executed when <em/regexp/
matches recipients of the message.

<tt/reply-hook/ is matched against the message you are <em/replying/
<bf/to/, instead of the message you are <em/sending/.  <tt/send-hook/ is
matched against all messages, both <em/new/ and <em/replies/.  <bf/Note:/
<tt/reply-hook/s are matched <bf/before/ the <tt/send-hook/, <bf/regardless/
of the order specified in the users's configuration file.

<tt/send2-hook/ is matched every time a message is changed, either
by editing it, or by using the compose menu to change its recipients
or subject.  <tt/send2-hook/ is executed after <tt/send-hook/, and
can, e.g., be used to set parameters such as the <ref id="sendmail"
name="&dollar;sendmail"> variable depending on the message's sender
address.

For each type of <tt/send-hook/ or <tt/reply-hook/, when multiple matches
occur, commands are executed in the order they are specified in the muttrc
(for that type of hook).

See <ref id="pattern_hook" name="Message Matching in Hooks"> for information on the exact format of <em/pattern/.

Example: <tt/send-hook mutt &dquot;set mime&lowbar;forward signature=''&dquot;/

Another typical use for this command is to change the values of the
<ref id="attribution" name="&dollar;attribution">, <ref id="signature"
name="&dollar;signature"> and <ref id="locale" name="&dollar;locale">
variables in order to change the language of the attributions and
signatures based upon the recipients.

<bf/Note:/ the send-hook's are only executed ONCE after getting the initial
list of recipients.  Adding a recipient after replying or editing the
message will NOT cause any send-hook to be executed.  Also note that
my_hdr commands which modify recipient headers, or the message's
subject, don't have any effect on the current message when executed
from a send-hook.

<!--}}}--> 

<sect>Change settings before formatting a message<label id="message-hook"> <!--{{{--> 
<p>
Usage: <tt/message-hook/ &lsqb;!&rsqb;<em/pattern/ <em/command/

This command can be used to execute arbitrary configuration commands
before viewing or formatting a message based upon information about the message.
<em/command/ is executed if the <em/pattern/ matches the message to be
displayed. When multiple matches occur, commands are executed in the order
they are specified in the muttrc.

See <ref id="pattern_hook" name="Message Matching in Hooks"> for
information on the exact format of <em/pattern/.

Example:
<tscreen><verb>
message-hook ~A 'set pager=builtin'
message-hook '~f freshmeat-news' 'set pager="less \"+/^  subject: .*\""'
</verb></tscreen>

<!--}}}--> 

<sect>Choosing the cryptographic key of the recipient<label id="crypt-hook"> <!--{{{--> 
<p>
Usage: <tt/crypt-hook/ <em/pattern/ <em/keyid/

When encrypting messages with PGP or OpenSSL, you may want to associate a certain
key with a given e-mail address automatically, either because the
recipient's public key can't be deduced from the destination address,
or because, for some reasons, you need to override the key Mutt-ng would
normally use.  The crypt-hook command provides a method by which you can
specify the ID of the public key to be used when encrypting messages to
a certain recipient.

The meaning of "key id" is to be taken broadly in this context:  You
can either put a numerical key ID here, an e-mail address, or even
just a real name.

<!--}}}--> 

<sect>Adding key sequences to the keyboard buffer<label id="push"> <!--{{{--> 
<p>
Usage: <tt/push/ <em/string/

This command adds the named string to the keyboard buffer. The string may
contain control characters, key names and function names like the sequence
string in the <ref id="macro" name="macro"> command. You may use it to
automatically run a sequence of commands at startup, or when entering
certain folders.

<!--}}}--> 

<sect>Executing functions<label id="exec"> <!--{{{--> 
<p>
Usage: <tt/exec/ <em/function/ &lsqb; <em/function/ ... &rsqb;

This command can be used to execute any function. Functions are
listed in the <ref id="functions" name="function reference">.
``exec function'' is equivalent to ``push &lt;function&gt;''.

<!--}}}--> 

<sect>Message Scoring<label id="score-command"> <!--{{{--> 

<p>
Usage: <tt/score/ <em/pattern/ <em/value/<newline>
Usage: <tt/unscore/ <em/pattern/ &lsqb; <em/pattern/ ... &rsqb;

<p>
In situations where you have to cope with a lot of emails, e.g.
when you read many different mailing lists, and take part in
discussions, it is always useful to have the important messages
marked and the annoying messages or the ones that you aren't
interested in deleted. For this purpose, mutt-ng features a
mechanism called ``scoring''.

<p>
When you use scoring, every message has a base score of 0. You
can then use the <tt/score/ command to define patterns and a
positive or negative value associated with it. When a pattern
matches a message, the message's score will be raised or lowered by
the amount of the value associated with the pattern.

<verb>
score "~f nion@muttng\.org" 50
score "~f @sco\.com" -100</verb>

<p>If the pattern matches, it is also possible to set the score
value of the current message to a certain value and then stop
evaluation:

<verb>
score "~f santaclaus@northpole\.int" =666</verb>

<p>What is important to note is that negative score values will be
rounded up to 0.

<p>To make scoring actually useful, the score must be applied in
some way.  That's what the <em/score thresholds/ are for. Currently,
there are three score thresholds:

<itemize>

  <item>flag threshold: when a message has a score value equal or higher
  than the flag threshold, it will be flagged.

  <item>read threshold: when a message has a score value equal or lower
  than the read threshold, it will be marked as read.

  <item>delete threshold: when a message has a score value equal or
  lower than the delete threshold, it will be marked as deleted.

</itemize>

<p>These three thresholds can be set via the variables <ref
id="score_threshold_flag"
name="&dollar;score&lowbar;threshold&lowbar;flag">, <ref
id="score_threshold_read"
name="&dollar;score&lowbar;threshold&lowbar;read">, <ref
id="score_threshold_delete"
name="&dollar;score&lowbar;threshold&lowbar;delete"> and.  By
default, <ref id="score_threshold_read"
name="&dollar;score&lowbar;threshold&lowbar;read"> and <ref
id="score_threshold_delete"
name="&dollar;score&lowbar;threshold&lowbar;delete"> are set to
<tt/-1/, which means that in the default threshold configuration no
message will ever get marked as read or deleted.

<p>Scoring gets especially interesting when combined with the <tt/color/ command
and the <tt>&tilde;n</tt> pattern:

<verb>
color index  black   yellow  "~n 10-"
color index  red     yellow  "~n 100-"</verb>

<p>The rules above mark all messages with a score between 10 and 99
with black and yellow, and messages with a score greater or equal
100 with red and yellow. This might be unusual to you if you're used
to e.g. slrn's scoring mechanism, but it is more flexible, as it
visually marks different scores.

<!--}}}--> 

<sect>Spam detection<label id="spam"> <!--{{{--> 
<p>
Usage: <tt/spam/ <em/pattern/ <em/format/<newline>
Usage: <tt/nospam/ <em/pattern/

Mutt-ng has generalized support for external spam-scoring filters.
By defining your spam patterns with the <tt/spam/ and <tt/nospam/
commands, you can <em/limit/, <em/search/, and <em/sort/ your
mail based on its spam attributes, as determined by the external
filter. You also can display the spam attributes in your index
display using the <tt/%H/ selector in the <ref id="index_format"
name="&dollar;index&lowbar;format"> variable. (Tip: try <tt/%?H?[%H] ?/
to display spam tags only when they are defined for a given message.)

Your first step is to define your external filter's spam patterns using
the <tt/spam/ command. <em/pattern/ should be a regular expression
that matches a header in a mail message. If any message in the mailbox
matches this regular expression, it will receive a ``spam tag'' or
``spam attribute'' (unless it also matches a <tt/nospam/ pattern -- see
below.) The appearance of this attribute is entirely up to you, and is
governed by the <em/format/ parameter. <em/format/ can be any static
text, but it also can include back-references from the <em/pattern/
expression. (A regular expression ``back-reference'' refers to a
sub-expression contained within parentheses.) <tt/%1/ is replaced with
the first back-reference in the regex, <tt/%2/ with the second, etc.

If you're using multiple spam filters, a message can have more than
one spam-related header. You can define <tt/spam/ patterns for each
filter you use. If a message matches two or more of these patterns, and
the &dollar;spam&lowbar;separator variable is set to a string, then the
message's spam tag will consist of all the <em/format/ strings joined
together, with the value of &dollar;spam&lowbar;separator separating
them.

For example, suppose I use DCC, SpamAssassin, and PureMessage. I might
define these spam settings:
<tscreen><verb>
spam "X-DCC-.*-Metrics:.*(....)=many"         "90+/DCC-%1"
spam "X-Spam-Status: Yes"                     "90+/SA"
spam "X-PerlMX-Spam: .*Probability=([0-9]+)%" "%1/PM"
set spam_separator=", "
</verb></tscreen>

If I then received a message that DCC registered with ``many'' hits
under the ``Fuz2'' checksum, and that PureMessage registered with a
97% probability of being spam, that message's spam tag would read
<tt>90+/DCC-Fuz2, 97/PM</tt>. (The four characters before ``=many'' in a
DCC report indicate the checksum used -- in this case, ``Fuz2''.)

If the &dollar;spam&lowbar;separator variable is unset, then each
spam pattern match supersedes the previous one. Instead of getting
joined <em/format/ strings, you'll get only the last one to match.

The spam tag is what will be displayed in the index when you use
<tt/%H/ in the <tt/&dollar;index&lowbar;format/ variable. It's also the
string that the <tt/~H/ pattern-matching expression matches against for
<em/search/ and <em/limit/ functions. And it's what sorting by spam
attribute will use as a sort key.

That's a pretty complicated example, and most people's actual
environments will have only one spam filter. The simpler your
configuration, the more effective mutt can be, especially when it comes
to sorting.

Generally, when you sort by spam tag, mutt will sort <em/lexically/ --
that is, by ordering strings alphnumerically. However, if a spam tag
begins with a number, mutt will sort numerically first, and lexically
only when two numbers are equal in value. (This is like UNIX's
<tt/sort -n/.) A message with no spam attributes at all -- that is, one
that didn't match <em/any/ of your <tt/spam/ patterns -- is sorted at
lowest priority. Numbers are sorted next, beginning with 0 and ranging
upward. Finally, non-numeric strings are sorted, with ``a'' taking lower
priority than ``z''. Clearly, in general, sorting by spam tags is most
effective when you can coerce your filter to give you a raw number. But
in case you can't, mutt can still do something useful.

The <tt/nospam/ command can be used to write exceptions to <tt/spam/
patterns. If a header pattern matches something in a <tt/spam/ command,
but you nonetheless do not want it to receive a spam tag, you can list a
more precise pattern under a <tt/nospam/ command.

If the <em/pattern/ given to <tt/nospam/ is exactly the same as the
<em/pattern/ on an existing <tt/spam/ list entry, the effect will be to
remove the entry from the spam list, instead of adding an exception.
Likewise, if the <em/pattern/ for a <tt/spam/ command matches an entry
on the <tt/nospam/ list, that <tt/nospam/ entry will be removed. If the
<em/pattern/ for <tt/nospam/ is ``*'', <em/all entries on both lists/
will be removed. This might be the default action if you use <tt/spam/
and <tt/nospam/ in conjunction with a <tt/folder-hook/.

You can have as many <tt/spam/ or <tt/nospam/ commands as you like.
You can even do your own primitive spam detection within mutt -- for
example, if you consider all mail from <tt/MAILER-DAEMON/ to be spam,
you can use a <tt/spam/ command like this:

<tscreen><verb>
spam "^From: .*MAILER-DAEMON"       "999"
</verb></tscreen>

<!--}}}--> 

<sect>Setting variables<label id="set"> <!--{{{--> 
<p>
Usage: <tt/set/ &lsqb;no|inv&rsqb;<em/variable/&lsqb;=<em/value/&rsqb; &lsqb; <em/variable/ ... &rsqb;<newline>
Usage: <tt/toggle/ <em/variable/ &lsqb;<em/variable/ ... &rsqb;<newline>
Usage: <tt/unset/ <em/variable/ &lsqb;<em/variable/ ... &rsqb;<newline>
Usage: <tt/reset/ <em/variable/ &lsqb;<em/variable/ ... &rsqb;

This command is used to set (and unset) <ref id="variables"
name="configuration variables">.  There are four basic types of variables:
boolean, number, string and quadoption.  <em/boolean/ variables can be
<em/set/ (true) or <em/unset/ (false).  <em/number/ variables can be
assigned a positive integer value.

<em/string/ variables consist of any number of printable characters.
<em/strings/ must be enclosed in quotes if they contain spaces or tabs.  You
may also use the ``C'' escape sequences <bf/&bsol;n/ and <bf/&bsol;t/ for
newline and tab, respectively.

<em/quadoption/ variables are used to control whether or not to be prompted
for certain actions, or to specify a default action.  A value of <em/yes/
will cause the action to be carried out automatically as if you had answered
yes to the question.  Similarly, a value of <em/no/ will cause the the
action to be carried out as if you had answered ``no.''  A value of
<em/ask-yes/ will cause a prompt with a default answer of ``yes'' and
<em/ask-no/ will provide a default answer of ``no.''

Prefixing a variable with ``no'' will unset it.  Example: <tt/set noaskbcc/.

For <em/boolean/ variables, you may optionally prefix the variable name with
<tt/inv/ to toggle the value (on or off).  This is useful when writing
macros.  Example: <tt/set invsmart&lowbar;wrap/.

The <tt/toggle/ command automatically prepends the <tt/inv/ prefix to all
specified variables.

The <tt/unset/ command automatically prepends the <tt/no/ prefix to all
specified variables.

Using the enter-command function in the <em/index/ menu, you can query the
value of a variable by prefixing the name of the variable with a question
mark:

<tscreen><verb>
set ?allow_8bit
</verb></tscreen>

The question mark is actually only required for boolean and quadoption 
variables.

The <tt/reset/ command resets all given variables to the compile time
defaults (hopefully mentioned in this manual). If you use the command
<tt/set/ and prefix the variable with ``&amp;'' this has the same
behavior as the reset command.

With the <tt/reset/ command there exists the special variable ``all'',
which allows you to reset all variables to their system defaults.

<!--}}}--> 

<sect>Reading initialization commands from another file<label id="source"> <!--{{{--> 
<p>
Usage: <tt/source/ <em/filename/ &lsqb; <em/filename/ ... &rsqb;

This command allows the inclusion of initialization commands
from other files.  For example, I place all of my aliases in
<tt>&tilde;/.mail&lowbar;aliases</tt> so that I can make my
<tt>&tilde;/.muttrc</tt> readable and keep my aliases private.

If the filename begins with a tilde (``&tilde;''), it will be expanded to the
path of your home directory.

If the filename ends with a vertical bar (|), then <em/filename/ is
considered to be an executable program from which to read input (eg.
<tt>source ~/bin/myscript|</tt>).

<!--}}}--> 

<sect>Removing hooks<label id="unhook"> <!--{{{--> 
<p>
Usage: <tt/unhook/ &lsqb; * | <em/hook-type/ &rsqb;

This command permits you to flush hooks you have previously defined.
You can either remove all hooks by giving the ``*'' character as an
argument, or you can remove all hooks of a specific type by saying
something like <tt/unhook send-hook/.

<!--}}}--> 

  <sect>Sharing Setups<label id="sect:sharingsetups"> <!--{{{--> 

    <sect1>Character Sets <!--{{{--> 

    <p>As users may run mutt-ng on different systems, the configuration
    must be maintained because it's likely that people want to use the
    setup everywhere they use mutt-ng. And mutt-ng tries to help where it
    can.

    <p>To not produce conflicts with different character sets, mutt-ng
    allows users to specify in which character set their configuration
    files are encoded. Please note that while reading the configuration
    files, this is only respected after the corresponding declaration
    appears. It's advised to put the following at the very beginning of a
    users muttngrc:

    <verb>
set config_charset = "..."</verb>

    <p>and replacing the dots with the actual character set. To avoid
    problems while maintaining the setup, vim user's may want to use
    modelines as show in:

    <verb>
# vim:fileencoding=...:</verb>

    <p>while, again, replacing the dots with the appropriate name. This
    tells vim as which character set to read and save the file.

    <!--}}}--> 

    <sect1>Modularization <!--{{{--> 

      <p>``Modularization'' means to divide the setup into several files
      while sorting the options or commands by topic. Especially for
      longer setups (e.g. with many hooks), this helps maintaining it
      and solving trouble.

      <p>When using separation, setups may be, as a whole or in
      fractions, shared over different systems.

    <!--}}}--> 

    <sect1>Conditional parts <!--{{{--> 

    <p>When using a configuration on different systems, the user may not
    always have influence on how mutt-ng is installed and which features
    it includes.

    <p>To solve this, mutt-ng contain a feature based on the ``ifdef''
    patch written for mutt. Its basic syntax is:

    <verb>
ifdef &lt;item&gt; &lt;command&gt;
ifndef &lt;item&gt; &lt;command&gt;</verb>

    <p>...whereby <tt/&lt;item&gt;/ can be one of:

    <itemize>

      <item>a function name

      <item>a variable name

      <item>a menu name

      <item>a feature name

    </itemize>

    <p>All available functions, variables and menus are documented
    elsewhere in this manual but ``features'' is specific to these two
    commands. To test for one, prefix one of the following keywords with
    <tt/feature&lowbar;/:

    <verb>
ncurses, slang, iconv, idn, dotlock, standalone, pop, nntp, imap, ssl,
gnutls, sasl, sasl2, libesmtp, compressed, color, classic_pgp,
classic_smime, gpgme, header_cache</verb>

    <p>As an example, one can use the following in
    <tt>&tilde;/.muttngrc</tt>:

    <verb>
ifdef feature_imap 'source ~/.mutt-ng/setup-imap'
ifdef feature_pop  'source ~/.mutt-ng/setup-pop'
ifdef feature_nntp 'source ~/.mutt-ng/setup-nntp'</verb>

    <p>...to only source <tt>&tilde;/.mutt-ng/setup-imap</tt> if IMAP
    support is built in, only source <tt>&tilde;/.mutt-ng/setup-pop</tt>
    if POP support is built in and only source
    <tt>&tilde;/.mutt-ng/setup-nntp</tt> if NNTP support is built in.

    <p>An example for testing for variable names can be used if users
    use different revisions of mutt-ng whereby the older one may not
    have a certain variable. To test for the availability of <ref
    id="imap_mail_check" name="&dollar;imap&lowbar;mail&lowbar;check">,
    use:

    <verb>
ifdef imap_mail_check 'set imap_mail_check = 300'</verb>

    <p>Provided for completeness is the test for menu names. To set <ref
    id="pager_index_lines"
    name="&dollar;pager&lowbar;index&lowbar;lines"> only if the pager
    menu is available, use:

    <verb>
ifdef pager 'set pager_index_lines = 10'</verb>

    <p>For completeness, too, the opposite of <tt/ifdef/ is provided:
    <tt/ifndef/ which only executes the command if the test fails. For
    example, the following two examples are equivalent:

    <verb>
ifdef feature_ncurses 'source ~/.mutt-ng/setup-ncurses'
ifndef feature_ncurses 'source ~/.mutt-ng/setup-slang'</verb>

    <p>...and...

    <verb>
ifdef feature_slang 'source ~/.mutt-ng/setup-slang'
ifndef feature_slang 'source ~/.mutt-ng/setup-ncurses'</verb>

  <!--}}}--> 


  <!--}}}--> 

<sect>Obsolete Variables <!--{{{--> 

<p>In the process of ensuring and creating more consistency, many
variables have been renamed and some of the old names were already
removed. Please see <ref id="sect_obsolete" name="Obsolete Variables">
for a complete list.

<!--}}}--> 

<!--}}}--> 

<chapt>Advanced Usage <!--{{{--> 

<sect>Regular Expressions<label id="regexp"> <!--{{{--> 
<p>
All string patterns in Mutt-ng including those in more complex
<ref id="patterns" name="patterns"> must be specified
using regular expressions (regexp) in the ``POSIX extended'' syntax (which
is more or less the syntax used by egrep and GNU awk).  For your
convenience, we have included below a brief description of this syntax.

The search is case sensitive if the pattern contains at least one upper
case letter, and case insensitive otherwise. Note that ``&bsol;''
must be quoted if used for a regular expression in an initialization
command: ``&bsol;&bsol;''.

A regular expression is a pattern that describes a set of strings.
Regular expressions are constructed analogously to arithmetic
expressions, by using various operators to combine smaller expressions.

Note that the regular expression can be enclosed/delimited by either &dquot;
or ' which is useful if the regular expression includes a white-space
character.  See <ref id="muttrc-syntax" name="Syntax of Initialization Files">
for more information on &dquot; and ' delimiter processing.  To match a
literal &dquot; or ' you must preface it with \ (backslash).

The fundamental building blocks are the regular expressions that match
a single character.  Most characters, including all letters and digits,
are regular expressions that match themselves.  Any metacharacter with
special meaning may be quoted by preceding it with a backslash.

The period ``.'' matches any single character.  The caret ``&circ;'' and
the dollar sign ``&dollar'' are metacharacters that respectively match
the empty string at the beginning and end of a line.

A list of characters enclosed by ``&lsqb;'' and ``&rsqb;'' matches any
single character in that list; if the first character of the list
is a caret ``&circ;'' then it matches any character <bf/not/ in the
list.  For example, the regular expression <bf/&lsqb;0123456789&rsqb;/
matches any single digit.  A range of ASCII characters may be specified
by giving the first and last characters, separated by a hyphen
``-''.  Most metacharacters lose their special meaning inside
lists.  To include a literal ``&rsqb;'' place it first in the list.
Similarly, to include a literal ``&circ;'' place it anywhere but first.
Finally, to include a literal hyphen ``-'' place it last.

Certain named classes of characters are predefined.  Character classes
consist of ``&lsqb;:'', a keyword denoting the class, and ``:&rsqb;''.
The following classes are defined by the POSIX standard:

<descrip>
<tag/&lsqb;:alnum:&rsqb;/
Alphanumeric characters.
<tag/&lsqb;:alpha:&rsqb;/
Alphabetic characters.
<tag/&lsqb;:blank:&rsqb;/
Space or tab characters.
<tag/&lsqb;:cntrl:&rsqb;/
Control characters.
<tag/&lsqb;:digit:&rsqb;/
Numeric characters.
<tag/&lsqb;:graph:&rsqb;/
Characters that are both printable and visible.  (A space is printable,
but not visible, while an ``a'' is both.)
<tag/&lsqb;:lower:&rsqb;/
Lower-case alphabetic characters.
<tag/&lsqb;:print:&rsqb;/
Printable characters (characters that are not control characters.)
<tag/&lsqb;:punct:&rsqb;/
Punctuation characters (characters that are not letter, digits, control
characters, or space characters).
<tag/&lsqb;:space:&rsqb;/
Space characters (such as space, tab and formfeed, to name a few).
<tag/&lsqb;:upper:&rsqb;/
Upper-case alphabetic characters.
<tag/&lsqb;:xdigit:&rsqb;/
Characters that are hexadecimal digits.
</descrip>

A character class is only valid in a regular expression inside the
brackets of a character list.  Note that the brackets in these
class names are part of the symbolic names, and must be included
in addition to the brackets delimiting the bracket list.  For
example, <bf/&lsqb;&lsqb;:digit:&rsqb;&rsqb;/ is equivalent to
<bf/&lsqb;0-9&rsqb;/.

Two additional special sequences can appear in character lists.  These
apply to non-ASCII character sets, which can have single symbols (called
collating elements) that are represented with more than one character,
as well as several characters that are equivalent for collating or
sorting purposes:

<descrip>
<tag/Collating Symbols/
A collating symbol is a multi-character collating element enclosed in
``&lsqb;.'' and ``.&rsqb;''.  For example, if ``ch'' is a collating
element, then <bf/&lsqb;&lsqb;.ch.&rsqb;&rsqb;/ is a regexp that matches
this collating element, while <bf/&lsqb;ch&rsqb;/ is a regexp that
matches either ``c'' or ``h''.
<tag/Equivalence Classes/
An equivalence class is a locale-specific name for a list of
characters that are equivalent. The name is enclosed in ``&lsqb;=''
and ``=&rsqb;''.  For example, the name ``e'' might be used to
represent all of ``&egrave;'' ``&eacute;'' and ``e''.  In this case,
<bf/&lsqb;&lsqb;=e=&rsqb;&rsqb;/ is a regexp that matches any of
``&egrave;'', ``&eacute;'' and ``e''.
</descrip>

A regular expression matching a single character may be followed by one
of several repetition operators:

<descrip>
<tag/?/
The preceding item is optional and matched at most once.
<tag/*/
The preceding item will be matched zero or more times.
<tag/+/
The preceding item will be matched one or more times.
<tag/&lcub;n&rcub;/
The preceding item is matched exactly <em/n/ times.
<tag/&lcub;n,&rcub;/
The preceding item is matched <em/n/ or more times.
<tag/&lcub;,m&rcub;/
The preceding item is matched at most <em/m/ times.
<tag/&lcub;n,m&rcub;/
The preceding item is matched at least <em/n/ times, but no more than
<em/m/ times.
</descrip>

Two regular expressions may be concatenated; the resulting regular
expression matches any string formed by concatenating two substrings
that respectively match the concatenated subexpressions.

Two regular expressions may be joined by the infix operator ``|'';
the resulting regular expression matches any string matching either
subexpression.

Repetition takes precedence over concatenation, which in turn takes
precedence over alternation.  A whole subexpression may be enclosed in
parentheses to override these precedence rules.

<bf/Note:/ If you compile Mutt-ng with the GNU <em/rx/ package, the
following operators may also be used in regular expressions:

<descrip>
<tag/&bsol;&bsol;y/
Matches the empty string at either the beginning or the end of a word.
<tag/&bsol;&bsol;B/
Matches the empty string within a word.
<tag/&bsol;&bsol;&lt;/
Matches the empty string at the beginning of a word.
<tag/&bsol;&bsol;&gt;/
Matches the empty string at the end of a word.
<tag/&bsol;&bsol;w/
Matches any word-constituent character (letter, digit, or underscore).
<tag/&bsol;&bsol;W/
Matches any character that is not word-constituent.
<tag/&bsol;&bsol;`/
Matches the empty string at the beginning of a buffer (string).
<tag/&bsol;&bsol;'/
Matches the empty string at the end of a buffer.
</descrip>

Please note however that these operators are not defined by POSIX, so
they may or may not be available in stock libraries on various systems.

<!--}}}--> 

<sect>Patterns <!--{{{--> 

<p>Mutt-ng's pattern language provides a simple yet effective way to
set up rules to match messages, e.g. for operations like tagging and
scoring. A pattern consists of one or more sub-pattern, which can be
logically grouped, ORed, and negated. For a complete listing of
these patterns, please refer to table <ref id="patterns"
name="Patterns"> in the Reference chapter.

<p>It must be noted that in this table, <tt/EXPR/, <tt/USER/,
<tt/ID/ and <tt/SUBJECT/ are regular expressions. For ranges, the
forms <tt/&lt;[MAX]/, <tt/&gt;>[MIN]/, <tt/[MIN]-/ and <tt/-[MAX]/
are also possible.

<sect1>Complex Patterns 

<p>It is possible to combine several sub-patterns to a more complex
pattern. The most simple possibility is to logically AND several
patterns by stringing them together:

<verb>
~s 'SPAM' ~U</verb>

<p>The pattern above matches all messages that contain ``SPAM'' in
the subject and are unread.

<p>To logical OR patterns, simply use the <tt/|/ operator. This one
especially useful when using local groups:

<verb>
~f ("nion@muttng\.org"|"ak@muttng\.org"|"pdmef@muttng\.org")
(~b mutt-ng|~s Mutt-ng)
!~x '@synflood\.at'</verb>

<p>The first pattern matches all messages that were sent by one of
the mutt-ng maintainers, while the seconds pattern matches all
messages that contain ``mutt-ng'' in the message body or ``Mutt-ng''
in the subject. The third pattern matches all messages that do not
contain ``@synflood\.at'' in the <tt/References:/ header, i.e.
messages that are not an (indirect) reply to one of my messages. A
pattern can be logicall negated using the <tt/!/ operator.

<sect1>Patterns and Dates 

<p>When using dates in patterns, the dates must be specified in a
special format, i.e.  <tt>DD/MM/YYYY</tt>. If you don't specify
month or year, they default to the current month or year. When using
date ranges, and you specify only the minimum or the maximum, the
specified date will be excluded, e.g. <tt>01/06/2005-</tt> matches
against all messages <em/after/ Juni 1st, 2005.

<p>It is also possible to use so-called ``error margins'' when
specifying date ranges.  You simply specify a date, and then the
error margin. This margin needs to contain the information whether
it goes ``forth'' or ``back'' in time, by using <tt/+/ and <tt/-/.
Then follows a number and a unit, i.e. <tt/y/ for years, <tt/m/ for
months, <tt/w/ for weeks and <tt/d/ for days. If you use the special
<tt/*/ sign, it means that the error margin goes to both
``directions'' in time.

<verb>
~d 01/01/2005+1y
~d 18/10/2004-2w
~d 28/12/2004*1d</verb>

<p>The first pattern matches all dates between January 1st, 2005 and
January 1st 2006.  The second pattern matches all dates between
October 18th, 2004 and October 4th 2004 (2 weeks before 18/10/2004),
while the third pattern matches all dates 1 day around December
28th, 2004 (i.e. Dec 27th, 28th and 29th).

<p>Relative dates are also very important, as they make it possible
to specify date ranges between a fixed number of units and the
current date. How this works can be seen in the following example:

<verb>
~d &gt;2w # messages older than two weeks
~d &lt;3d # messages newer than 3 days
~d =1m # messages that are exactly one month old</verb>

<!--}}}--> 

  <sect>Format Strings <!--{{{--> 

    <sect1>Introduction <!--{{{--> 
  
      <p>The so called <em/Format Strings/ offer great flexibility when
      configuring mutt-ng. In short, they describe what items to print
      out how in menus and status messages.

      <p>Basically, they work as this: for different menus and bars,
      there's a variable specifying the layout. For every item
      available, there is a so called <em/expando/.
      
      <p>For example, when running mutt-ng on different machines or
      different versions for testing purposes, it may be interesting to
      have the following information always printed on screen when one
      is in the index:

      <itemize>

        <item>the current hostname

        <item>the current mutt-ng version number

      </itemize>

      <p>The setting for the status bar of the index is controlled via the
      <ref id="status_format" name="&dollar;status&lowbar;format">
      variable. For the hostname and version string, there's an expando
      for <tt>&dollar;status&lowbar;format</tt>: <tt/%h/ expands to the
      hostname and <tt/%v/ to the version string. When just configuring:

      <verb>
set status_format = "%v on %h: ..."</verb>

      <p>mutt-ng will replace the sequence <tt/%v/ with the version string
      and <tt/%h/ with the host's name. When you are, for example, running
      mutt-ng version <tt/1.5.9i/ on host <tt/mailhost/, you'll see the
      following when you're in the index:

      <verb>
Mutt-ng 1.5.9i on mailhost: ...</verb>

      <p>In the index, there're more useful information one could want to 
      see:

      <itemize>

        <item>which mailbox is open

        <item>how man new, flagged or postponed messages

        <item>...

      </itemize>

      <p>To include the mailbox' name is as easy as:

      <verb>
set status_format = "%v on %h: %B: ...</verb>

      <p>When the currently opened mailbox is <tt/Inbox/, this will be expanded
      to:

      <verb>
Mutt-ng 1.5.9i on mailhost: Inbox: ...</verb>
      
      <p>For the number of certain types of messages, one more feature of the format
      strings is extremely useful. If there aren't messages of a certain type, it
      may not be desired to print just that there aren't any but instead only
      print something if there are any.

    <!--}}}--> 

    <sect1>Conditional Expansion <!--{{{--> 
      
      <p>To only print the number of messages if there are new messages in
      the current mailbox, further extend
      <tt/&dollar;status&lowbar;format/ to:

      <verb>
set status_format = "%v on %h: %B %?n?%n new? ...</verb>

      <p>This feature is called <em/nonzero-printing/ and works as this:
      some expandos may be optionally printed nonzero, i.e.  a portion
      of the format string is only evaluated if the value of the expando
      is different from zero. The basic syntax is:

      <verb>
%?<item>?<string if nonzero>?</verb>

      <p>which tells mutt-ng to only look at <tt>&lt;string if
      nonzero&gt;</tt> if the value of the <tt>%&lt;item%gt;</tt>
      expando is different from zero. In our example, we used <tt/n/ as
      the expando to check for and <tt/%n new/ as the optional nonzero
      string.

      <p>But this is not all: this feature only offers one alternative: 
      ``print something if not zero.'' Mutt-ng does, as you might guess, 
      also provide a logically complete version: ``if zero, print 
      something and else print something else.'' This is achieved by the 
      following syntax for those expandos which may be printed nonzero:

      <verb>
%?<item>?<string if nonzero>&<string if zero>?</verb>

      <p>Using this we can make mutt-ng to do the following:

      <itemize>

        <item> make it print ``<em/n/ new messages'' whereby <em/n/ is the
          count but only if there new ones

        <item> and make it print ``no new messages'' if there aren't any

      </itemize>

      <p>The corresponding configuration is:

      <verb>
set status_format = "%v on %h: %B: %?n?%n new messages&amp;no new messages? ...</verb>

      <p>This doubles the use of the ``new messages'' string because it'll get
      always printed. Thus, it can be shortened to:

      <verb>
set status_format = "%v on %h: %B: %?n?%n&amp;no? new messages ...</verb>

      <p>As you might see from this rather simple example, one can create
      very complex but fancy status messages. Please see the reference
      chapter for expandos and those which may be printed nonzero.

    <!--}}}--> 
 
    <sect1>Modifications and Padding <!--{{{--> 

      <p>Besides the information given so far, there're even more features of
      format strings:

      <itemize>

        <item>When specifying <tt>%&lowbar;&lt;item&gt;</tt> instead of
          just <tt>%&lt;item&gt;</tt>, mutt-ng will convert all
          characters in the expansion of <tt>&lt;item&gt;</tt> to
          lowercase.

        <item>When specifying <tt>%:&lt;item&gt;</tt> instead of just
          <tt>%&lt;item&gt;</tt>, mutt-ng will convert all dots in the
          expansion of <tt>&lt;item&gt;</tt> to underscores
          (<tt>&lowbar;</tt>).

      </itemize>
    
      <p>Also, there's a feature called <em/Padding/ supplied by the
      following two expandos: <tt/%|X/ and <tt/%&gt;X/.

      <descrip>

        <tag><tt>%|X</tt></tag> When this occurs, mutt-ng will fill the
          rest of the line with the character <tt/X/. In our example,
          filling the rest of the line with dashes is done by setting:

          <verb>
set status_format = "%v on %h: %B: %?n?%n&amp;no? new messages %|-"</verb>

        <tag><tt>%&gt;X</tt></tag> Since the previous expando stops at
          the end of line, there must be a way to fill the gap between
          two items via the <tt>%&gt;X</tt> expando: it puts as many
          characters <tt>X</tt> in between two items so that the rest of
          the line will be right-justified. For example, to not put the
          version string and hostname of our example on the left but on
          the right and fill the gap with spaces, one might use (note
          the space after <tt>%&gt;</tt>):

          <verb>
set status_format = "%B: %?n?%n&amp;no? new messages %> (%v on %h)"</verb>

      </descrip>

    <!--}}}--> 
 
  <!--}}}--> 
 
<sect>Using Tags <!--{{{--> 
<p>

Sometimes it is desirable to perform an operation on a group of
messages all at once rather than one at a time.  An example might be
to save messages to a mailing list to a separate folder, or to
delete all messages with a given subject.  To tag all messages
matching a pattern, use the tag-pattern function, which is bound to
``shift-T'' by default.  Or you can select individual messages by
hand using the ``tag-message'' function, which is bound to ``t'' by
default.  See <ref id="patterns" name="patterns"> for Mutt-ng's pattern
matching syntax.

Once you have tagged the desired messages, you can use the
``tag-prefix'' operator, which is the ``;'' (semicolon) key by default.
When the ``tag-prefix'' operator is used, the <bf/next/ operation will
be applied to all tagged messages if that operation can be used in that
manner.  If the <ref id="auto_tag" name="&dollar;auto&lowbar;tag">
variable is set, the next operation applies to the tagged messages
automatically, without requiring the ``tag-prefix''.

In <ref id="macro" name="macros"> or <ref id="push" name="push"> commands,
you can use the ``tag-prefix-cond'' operator.  If there are no tagged
messages, mutt will "eat" the rest of the macro to abort it's execution.
Mutt-ng will stop "eating" the macro when it encounters the ``end-cond''
operator;  after this operator the rest of the macro will be executed as
normal.

<!--}}}--> 

<sect>Using Hooks<label id="hooks"> <!--{{{--> 
<p>
A <em/hook/ is a concept borrowed from the EMACS editor which allows you to
execute arbitrary commands before performing some operation.  For example,
you may wish to tailor your configuration based upon which mailbox you are
reading, or to whom you are sending mail.  In the Mutt-ng world, a <em/hook/
consists of a <ref id="regexp" name="regular expression"> or
<ref id="patterns" name="pattern"> along with a
configuration option/command.  See
<itemize>
<item><ref id="folder-hook" name="folder-hook">
<item><ref id="send-hook" name="send-hook">
<item><ref id="message-hook" name="message-hook">
<item><ref id="save-hook" name="save-hook">
<item><ref id="mbox-hook" name="mbox-hook">
<item><ref id="fcc-hook" name="fcc-hook">
<item><ref id="fcc-save-hook" name="fcc-save-hook">
</itemize>
for specific details on each type of <em/hook/ available.

<bf/Note:/ if a hook changes configuration settings, these changes remain
effective until the end of the current mutt session. As this is generally
not desired, a default hook needs to be added before all other hooks to
restore configuration defaults. Here is an example with send-hook and the
my_hdr directive:

<tscreen><verb>
send-hook . 'unmy_hdr From:'
send-hook ~C'^b@b\.b$' my_hdr from: c@c.c
</verb></tscreen>

<sect1>Message Matching in Hooks<label id="pattern_hook">
<p>
Hooks that act upon messages (<tt/send-hook, save-hook, fcc-hook,
message-hook/) are evaluated in a slightly different manner.  For the other
types of hooks, a <ref id="regexp" name="regular expression"> is
sufficient.  But in dealing with messages a finer grain of control is
needed for matching since for different purposes you want to match
different criteria.

Mutt-ng allows the use of the <ref id="patterns" name="search pattern">
language for matching messages in hook commands.  This works in
exactly the same way as it would when <em/limiting/ or
<em/searching/ the mailbox, except that you are restricted to those
operators which match information mutt extracts from the header of
the message (i.e.  from, to, cc, date, subject, etc.).

For example, if you wanted to set your return address based upon sending
mail to a specific address, you could do something like:
<tscreen><verb>
send-hook '~t ^me@cs\.hmc\.edu$' 'my_hdr From: Mutt-ng User <user@host>'
</verb></tscreen>
which would execute the given command when sending mail to
<em/me@cs.hmc.edu/.

However, it is not required that you write the pattern to match using the
full searching language.  You can still specify a simple <em/regular
expression/ like the other hooks, in which case Mutt-ng will translate your
pattern into the full language, using the translation specified by the 
<ref id="default_hook" name="&dollar;default&lowbar;hook"> variable.  The
pattern is translated at the time the hook is declared, so the value of 
<ref id="default_hook" name="&dollar;default&lowbar;hook"> that is in effect
at that time will be used.

<!--}}}--> 

<sect>Using the sidebar<label id="sidebar"> <!--{{{--> 
<p>
The sidebar, a feature specific to Mutt-ng, allows you to use a mailbox listing 
which looks very similar to the ones you probably know from GUI mail clients.
The sidebar lists all specified mailboxes, shows the number in each
and highlights the ones with new email
Use the following configuration commands:
<tscreen><verb>
set sidebar_visible="yes"
set sidebar_width=25
</verb></tscreen>

If you want to specify the mailboxes you can do so with:
<tscreen><verb>
set mbox='=INBOX'
mailboxes INBOX \
          MBOX1 \
          MBOX2 \
          ...
</verb></tscreen>

You can also specify the colors for mailboxes with new mails by using:
<tscreen><verb>
color sidebar_new red black
color sidebar white black
</verb></tscreen>

The available functions are:
<tscreen><verb>
sidebar-scroll-up      Scrolls the mailbox list up 1 page
sidebar-scroll-down    Scrolls the mailbox list down 1 page
sidebar-next           Highlights the next mailbox
sidebar-next-new       Highlights the next mailbox with new mail
sidebar-previous       Highlights the previous mailbox
sidebar-open           Opens the currently highlighted mailbox
</verb></tscreen>

Reasonable key bindings look e.g. like this:
<tscreen><verb>
bind index \Cp sidebar-prev
bind index \Cn sidebar-next
bind index \Cb sidebar-open
bind pager \Cp sidebar-prev
bind pager \Cn sidebar-next
bind pager \Cb sidebar-open

macro index B ':toggle sidebar_visible^M'
macro pager B ':toggle sidebar_visible^M'
</verb></tscreen>

You can then go up and down by pressing Ctrl-P and Ctrl-N, and 
switch on and off the sidebar simply by pressing 'B'.

<!--}}}--> 

<sect>External Address Queries<label id="query"> <!--{{{--> 
<p>
Mutt-ng supports connecting to external directory databases such as LDAP,
ph/qi, bbdb, or NIS through a wrapper script which connects to mutt
using a simple interface.  Using the <ref id="query_command"
name="&dollar;query&lowbar;command"> variable, you specify the wrapper
command to use.  For example:

<tscreen><verb>
set query_command = "mutt_ldap_query.pl '%s'"
</verb></tscreen>

The wrapper script should accept the query on the command-line.  It
should return a one line message, then each matching response on a
single line, each line containing a tab separated address then name then
some other optional information.  On error, or if there are no matching
addresses, return a non-zero exit code and a one line error message.

An example multiple response output:
<tscreen><verb>
Searching database ... 20 entries ... 3 matching:
me@cs.hmc.edu           Michael Elkins  mutt dude
blong@fiction.net       Brandon Long    mutt and more
roessler@guug.de        Thomas Roessler mutt pgp
</verb></tscreen>

There are two mechanisms for accessing the query function of mutt.  One
is to do a query from the index menu using the query function (default: Q).
This will prompt for a query, then bring up the query menu which will
list the matching responses.  From the query menu, you can select
addresses to create aliases, or to mail.  You can tag multiple addresses
to mail, start a new query, or have a new query appended to the current
responses.

The other mechanism for accessing the query function is for address
completion, similar to the alias completion.  In any prompt for address
entry, you can use the complete-query function (default: ^T) to run a
query based on the current address you have typed.  Like aliases, mutt
will look for what you have typed back to the last space or comma.  If
there is a single response for that query, mutt will expand the address
in place.  If there are multiple responses, mutt will activate the query
menu.  At the query menu, you can select one or more addresses to be
added to the prompt.

<!--}}}--> 

<sect>Mailbox Formats <!--{{{--> 
<p>
Mutt-ng supports reading and writing of four different mailbox formats:
mbox, MMDF, MH and Maildir.  The mailbox type is autodetected, so there
is no need to use a flag for different mailbox types.  When creating new
mailboxes, Mutt-ng uses the default specified with the <ref id="mbox_type"
name="&dollar;mbox&lowbar;type"> variable.

<bf/mbox/.  This is the most widely used mailbox format for UNIX.  All
messages are stored in a single file.  Each message has a line of the form:

<tscreen><verb>
From me@cs.hmc.edu Fri, 11 Apr 1997 11:44:56 PST
</verb></tscreen>

to denote the start of a new message (this is often referred to as the
``From&lowbar;'' line).

<bf/MMDF/.  This is a variant of the <em/mbox/ format.  Each message is
surrounded by lines containing ``^A^A^A^A'' (four control-A's).

<bf/MH/. A radical departure from <em/mbox/ and <em/MMDF/, a mailbox
consists of a directory and each message is stored in a separate file.
The filename indicates the message number (however, this is may not
correspond to the message number Mutt-ng displays). Deleted messages are
renamed with a comma (,) prepended to the filename. <bf/Note:/ Mutt
detects this type of mailbox by looking for either <tt/.mh&lowbar;sequences/
or <tt/.xmhcache/ (needed to distinguish normal directories from MH
mailboxes).

<bf/Maildir/.  The newest of the mailbox formats, used by the Qmail MTA (a
replacement for sendmail).  Similar to <em/MH/, except that it adds three
subdirectories of the mailbox: <em/tmp/, <em/new/ and <em/cur/.  Filenames
for the messages are chosen in such a way they are unique, even when two
programs are writing the mailbox over NFS, which means that no file locking
is needed.

<!--}}}--> 

<sect>Mailbox Shortcuts<label id="shortcuts"> <!--{{{--> 
<p>
There are a number of built in shortcuts which refer to specific mailboxes.
These shortcuts can be used anywhere you are prompted for a file or mailbox
path.

<itemize>
<item>! -- refers to your <ref id="spoolfile" name="&dollar;spoolfile"> (incoming) mailbox
<item>&gt; -- refers to your <ref id="mbox" name="&dollar;mbox"> file
<item>&lt; -- refers to your <ref id="record" name="&dollar;record"> file
<item>^ -- refers to the current mailbox
<item>- or !! -- refers to the file you've last visited
<item>&tilde; -- refers to your home directory
<item>= or + -- refers to your <ref id="folder" name="&dollar;folder"> directory
<item>@<em/alias/ -- refers to the <ref id="save-hook" 
name="default save folder"> as determined by the address of the alias
</itemize>

<!--}}}--> 

<sect>Handling Mailing Lists<label id="using_lists"> <!--{{{--> 
<p>

Mutt-ng has a few configuration options that make dealing with large
amounts of mail easier.  The first thing you must do is to let Mutt
know what addresses you consider to be mailing lists (technically
this does not have to be a mailing list, but that is what it is most
often used for), and what lists you are subscribed to.  This is
accomplished through the use of the <ref id="lists"
name="lists and subscribe"> commands in your muttrc.

Now that Mutt-ng knows what your mailing lists are, it can do several
things, the first of which is the ability to show the name of a list
through which you received a message (i.e., of a subscribed list) in
the <em/index/ menu display.  This is useful to distinguish between
personal and list mail in the same mailbox.  In the <ref id="index_format"
name="&dollar;index&lowbar;format"> variable, the escape ``&percnt;L''
will return the string ``To &lt;list&gt;'' when ``list'' appears in the
``To'' field, and ``Cc &lt;list&gt;'' when it appears in the ``Cc''
field (otherwise it returns the name of the author).

Often times the ``To'' and ``Cc'' fields in mailing list messages
tend to get quite large. Most people do not bother to remove the
author of the message they are reply to from the list, resulting in
two or more copies being sent to that person.  The ``list-reply''
function, which by default is bound to ``L'' in the <em/index/ menu
and <em/pager/, helps reduce the clutter by only replying to the
known mailing list addresses instead of all recipients (except as
specified by <tt/Mail-Followup-To/, see below).

Mutt-ng also supports the <tt/Mail-Followup-To/ header.  When you send
a message to a list of recipients which includes one or several
subscribed mailing lists, and if the <ref id="followup_to"
name="&dollar;followup&lowbar;to"> option is set, mutt will generate
a Mail-Followup-To header which contains all the recipients to whom
you send this message, but not your address. This indicates that
group-replies or list-replies (also known as ``followups'') to this
message should only be sent to the original recipients of the
message, and not separately to you - you'll receive your copy through
one of the mailing lists you are subscribed to.

Conversely, when group-replying or list-replying to a message which
has a <tt/Mail-Followup-To/ header, mutt will respect this header if
the <ref id="honor_followup_to"
name="&dollar;honor&lowbar;followup&lowbar;to"> configuration
variable is set.  Using list-reply will in this case also make sure
that the reply goes to the mailing list, even if it's not specified
in the list of recipients in the <tt/Mail-Followup-To/.

Note that, when header editing is enabled, you can create a
<tt/Mail-Followup-To/ header manually.  Mutt-ng will only auto-generate
this header if it doesn't exist when you send the message.


The other method some mailing list admins use is to generate a
``Reply-To'' field which points back to the mailing list address rather
than the author of the message.  This can create problems when trying
to reply directly to the author in private, since most mail clients
will automatically reply to the address given in the ``Reply-To''
field.  Mutt-ng uses the <ref id="reply_to" name="&dollar;reply&lowbar;to">
variable to help decide which address to use.  If set to <em/ask-yes/ or
<em/ask-no/, you will be
prompted as to whether or not you would like to use the address given in
the ``Reply-To'' field, or reply directly to the address given in the
``From'' field.  When set to <em/yes/, the ``Reply-To'' field will be used when
present.

The ``X-Label:'' header field can be used to further identify mailing
lists or list subject matter (or just to annotate messages
individually).  The <ref id="index_format"
name="&dollar;index&lowbar;format"> variable's ``&percnt;y'' and
``&percnt;Y'' escapes can be used to expand ``X-Label:'' fields in the
index, and Mutt-ng's pattern-matcher can match regular expressions to
``X-Label:'' fields with the ``&tilde;y'' selector.  ``X-Label:'' is not a
standard message header field, but it can easily be inserted by procmail
and other mail filtering agents.

Lastly, Mutt-ng has the ability to <ref id="sort" name="sort"> the mailbox into
<ref id="threads" name="threads">.  A thread is a group of messages which all relate to the same
subject.  This is usually organized into a tree-like structure where a
message and all of its replies are represented graphically.  If you've ever
used a threaded news client, this is the same concept.  It makes dealing
with large volume mailing lists easier because you can easily delete
uninteresting threads and quickly find topics of value.

<!--}}}--> 

<sect>Editing threads <!--{{{--> 
<p>
Mutt-ng has the ability to dynamically restructure threads that are broken
either by misconfigured software or bad behavior from some
correspondents. This allows to clean your mailboxes formats) from these
annoyances which make it hard to follow a discussion.

<sect1>Linking threads
<p>

Some mailers tend to "forget" to correctly set the "In-Reply-To:" and
"References:" headers when replying to a message. This results in broken
discussions because Mutt-ng has not enough information to guess the correct
threading.
You can fix this by tagging the reply, then moving to the parent message
and using the ``link-threads'' function (bound to & by default). The
reply will then be connected to this "parent" message.

You can also connect multiple children at once, tagging them and using the
tag-prefix command (';') or the auto_tag option.

<sect1>Breaking threads
<p>

On mailing lists, some people are in the bad habit of starting a new
discussion by hitting "reply" to any message from the list and changing
the subject to a totally unrelated one.
You can fix such threads by using the ``break-thread'' function (bound
by default to #), which will turn the subthread starting from the
current message into a whole different thread.

<!--}}}--> 

<sect>Delivery Status Notification (DSN) Support<label id="dsn"> <!--{{{--> 
<p>

RFC1894 defines a set of MIME content types for relaying information
about the status of electronic mail messages.  These can be thought of as
``return receipts.''

Users can make use of it in one of the following two ways:

<itemize>
  <item>Berkeley sendmail 8.8.x currently has some command line options
    in which the mail client can make requests as to what type of status
    messages should be returned.
  <item>The SMTP support via libESMTP supports it, too.
</itemize>

To support this, there are two variables:

<itemize>

  <item><ref id="dsn_notify" name="&dollar;dsn&lowbar;notify"> is used
    to request receipts for different results (such as failed message,
    message delivered, etc.).

  <item><ref id="dsn_return" name="&dollar;dsn&lowbar;return"> requests
    how much of your message should be returned with the receipt
    (headers or full message).

</itemize>

Please see the reference chapter for possible values.

<!--}}}--> 

<sect>POP3 Support (OPTIONAL) <!--{{{--> 
<p>

If Mutt-ng was compiled with POP3 support (by running the <em/configure/
script with the <em/--enable-pop/ flag), it has the ability to work
with mailboxes located on a remote POP3 server and fetch mail for local
browsing.

You can access the remote POP3 mailbox by selecting the folder
<tt>pop://popserver/</tt>.

You can select an alternative port by specifying it with the server, i.e.:
<tt>pop://popserver:port/</tt>.

You can also specify different username for each folder, i.e.:
<tt>pop://username@popserver[:port]/</tt>.

Polling for new mail is more expensive over POP3 than locally. For this
reason the frequency at which Mutt-ng will check for mail remotely can be
controlled by the
<ref id="pop_mail_check" name="&dollar;pop&lowbar;mail&lowbar;check">
variable, which defaults to every 60 seconds.

If Mutt-ng was compiled with SSL support (by running the <em/configure/
script with the <em/--with-ssl/ flag), connections to POP3 servers
can be encrypted. This naturally requires that the server supports
SSL encrypted connections. To access a folder with POP3/SSL, you should
use pops: prefix, ie:
<tt>pops://[username@]popserver[:port]/</tt>.

Another way to access your POP3 mail is the <em/fetch-mail/ function
(default: G).  It allows to connect to <ref id="pop_host"
name="pop&lowbar;host">, fetch all your new mail and place it in the
local <ref id="spoolfile" name="spoolfile">.  After this
point, Mutt-ng runs exactly as if the mail had always been local.

<bf/Note:/ If you only need to fetch all messages to local mailbox
you should consider using a specialized program, such as <htmlurl
url="http://www.ccil.org/~esr/fetchmail" name="fetchmail">

<!--}}}--> 

<sect>IMAP Support (OPTIONAL) <!--{{{--> 
<p>

If Mutt-ng was compiled with IMAP support (by running the <em/configure/
script with the <em/--enable-imap/ flag), it has the ability to work
with folders located on a remote IMAP server.

You can access the remote inbox by selecting the folder
<tt>imap://imapserver/INBOX</tt>, where <tt/imapserver/ is the name of the
IMAP server and <tt/INBOX/ is the special name for your spool mailbox on
the IMAP server. If you want to access another mail folder at the IMAP
server, you should use <tt>imap://imapserver/path/to/folder</tt> where
<tt>path/to/folder</tt> is the path of the folder you want to access.

You can select an alternative port by specifying it with the server, i.e.:
<tt>imap://imapserver:port/INBOX</tt>.

You can also specify different username for each folder, i.e.:
<tt>imap://username@imapserver[:port]/INBOX</tt>.

If Mutt-ng was compiled with SSL support (by running the <em/configure/
script with the <em/--with-ssl/ flag), connections to IMAP servers
can be encrypted. This naturally requires that the server supports
SSL encrypted connections. To access a folder with IMAP/SSL, you should
use <tt>imaps://[username@]imapserver[:port]/path/to/folder</tt> as your 
folder path.

Pine-compatible notation is also supported, i.e.
<tt>{[username@]imapserver[:port][/ssl]}path/to/folder</tt>

Note that not all servers use / as the hierarchy separator.  Mutt-ng should
correctly notice which separator is being used by the server and convert
paths accordingly.

When browsing folders on an IMAP server, you can toggle whether to look
at only the folders you are subscribed to, or all folders with the
<em/toggle-subscribed/ command.  See also the 
<ref id="imap_list_subscribed"
name="&dollar;imap&lowbar;list&lowbar;subscribed"> variable.

Polling for new mail on an IMAP server can cause noticeable delays. So, you'll
want to carefully tune the
<ref id="imap_mail_check" name="&dollar;imap&lowbar;mail&lowbar;check">
and
<ref id="timeout" name="&dollar;timeout">
variables.

Note that if you are using mbox as the mail store on UW servers prior to
v12.250, the server has been reported to disconnect a client if another client
selects the same folder.

<sect1>The Folder Browser
<p>

As of version 1.2, mutt supports browsing mailboxes on an IMAP
server. This is mostly the same as the local file browser, with the
following differences:
<itemize>
<item>Instead of file permissions, mutt displays the string "IMAP",
  possibly followed by the symbol "+", indicating
  that the entry contains both messages and subfolders. On
  Cyrus-like servers folders will often contain both messages and
  subfolders. 
<item>For the case where an entry can contain both messages and
  subfolders, the selection key (bound to <tt>enter</tt> by default)
  will choose to descend into the subfolder view. If you wish to view
  the messages in that folder, you must use <tt>view-file</tt> instead
  (bound to <tt>space</tt> by default).
<item>You can create, delete and rename mailboxes with the
  <tt>create-mailbox</tt>, <tt>delete-mailbox</tt>, and
  <tt>rename-mailbox</tt> commands (default bindings: <tt>C</tt>,
  <tt>d</tt> and <tt>r</tt>, respectively). You may also
  <tt>subscribe</tt> and <tt>unsubscribe</tt> to mailboxes (normally
  these are bound to <tt>s</tt> and <tt>u</tt>, respectively).
</itemize>

<sect1>Authentication
<p>

Mutt-ng supports four authentication methods with IMAP servers: SASL,
GSSAPI, CRAM-MD5, and LOGIN (there is a patch by Grant Edwards to add
NTLM authentication for you poor exchange users out there, but it has
yet to be integrated into the main tree). There is also support for
the pseudo-protocol ANONYMOUS, which allows you to log in to a public
IMAP server without having an account. To use ANONYMOUS, simply make
your username blank or "anonymous".
<p>
SASL is a special super-authenticator, which selects among several protocols
(including GSSAPI, CRAM-MD5, ANONYMOUS, and DIGEST-MD5) the most secure
method available on your host and the server. Using some of these methods
(including DIGEST-MD5 and possibly GSSAPI), your entire session will be
encrypted and invisible to those teeming network snoops. It is the best
option if you have it. To use it, you must have the Cyrus SASL library
installed on your system and compile mutt with the <em/--with-sasl/ flag.
<p>
Mutt-ng will try whichever methods are compiled in and available on the server,
in the following order: SASL, ANONYMOUS, GSSAPI, CRAM-MD5, LOGIN.

There are a few variables which control authentication: 
<itemize>
<item><ref id="imap_user" name="&dollar;imap&lowbar;user"> - controls
  the username under which you request authentication on the IMAP server,
  for all authenticators. This is overridden by an explicit username in
  the mailbox path (i.e. by using a mailbox name of the form
  <tt/{user@host}/).
<item><ref id="imap_pass" name="&dollar;imap&lowbar;pass"> - a
  password which you may preset, used by all authentication methods where
  a password is needed.
<item><ref id="imap_authenticators"
  name="&dollar;imap&lowbar;authenticators"> - a colon-delimited list of IMAP
  authentication methods to try, in the order you wish to try them. If
  specified, this overrides mutt's default (attempt everything, in the order
  listed above).
</itemize>

<!--}}}--> 

<sect>NNTP Support (OPTIONAL)<label id="reading_news"> <!--{{{--> 

<p>If compiled with ``--enable-nntp'' option, Mutt-ng can read news from
a newsserver via NNTP.  You can open a newsgroup with the
``change-newsgroup'' function from the index/pager which is by default
bound to <tt/i/.

<p>The Default newsserver can be obtained from the
<tt/&dollar;NNTPSERVER/ environment variable. Like other news readers,
info about subscribed newsgroups is saved in a file as specified by the
<ref id="nntp_newsrc" name="&dollar;nntp&lowbar;newsrc"> variable.
Article headers are cached and can be loaded from a file when a
newsgroup is entered instead loading from newsserver; currently, this
caching mechanism still is different from the header caching for
maildir/IMAP.

<sect1>Again: Scoring <!--{{{--> 

  <p>Especially for Usenet, people often ask for advanced filtering
  and scoring functionality. Of course, mutt-ng has scoring and
  allows a killfile, too. How to use a killfile has been discussed
  in <ref id="score-command" name="Message scoring">.

  <p>What has not been discusses in detail is mutt-ng's built-in
  realname filter. For may newsreaders including those for
  ``advanced users'' like <em/slrn/ or <em/tin/, there are frequent
  request for such functionality. The solutions offered often are
  complicated regular expressions.

  <p>In mutt-ng this is as easy as

  <verb>
score ~* =42
  </verb>

  <p>This tells mutt-ng to apply a score of 42 to all messages whose
  sender specified a valid realname and a valid email address. Using

  <verb>
score !~* =42
  </verb>

  <p>on the contrary applies a score of 42 to all messages <em/not/
  matching those criteria which are very strict:

  <itemize>

    <item>Email addresses must be valid according to RFC 2822, see
    <htmlurl url="ftp://ftp.rfc-editor.org/in-notes/rfc2822.txt"
    name="&lt;ftp://ftp.rfc-editor.org/in-notes/rfc2822.txt&gt;">

    <item>the name must consist of at least 2 fields whereby a field
    must not end in a dot. This means that ``Joe User'' and ``Joe A.
    User'' are valid while ``J. User'' and ``J. A. User'' aren't.

    <item>it's assumed that users are interested in reading their
    own mail and mail from people who they have defined an alias for
    so that those 2 groups of messages are excluded from the strict
    rules.

  </itemize>

  <!--}}}--> 

<!--}}}--> 

<sect>SMTP Support (OPTIONAL) <!--{{{--> 

<p>Mutt-ng can be built using a library called ``libESMTP'' which
provides SMTP functionality. When <tt/configure/ was called with
<tt/--with-libesmtp/ or the output <tt>muttng -v</tt> contains
<tt>+USE_LIBESMTP</tt>, this will be or is the case already. The SMTP
support includes support for Delivery Status Notification (see <ref
id="dsn" name="Delivery Status Notification"> section) as well as
handling the <tt/8BITMIME/ flag controlled via <ref id="use_8bitmime"
name="&dollar;use&lowbar;8bitmime">.

<p>To enable sending mail directly via SMTP without an MTA such as
Postfix or SSMTP and the like, simply set the <ref id="smtp_host"
name="&dollar;smtp&lowbar;host"> variable pointing to your SMTP server.

<p>Authentication mechanisms are available via the <ref id="smtp_user"
name="&dollar;smtp&lowbar;user"> and <ref id="smtp_pass"
name="&dollar;smtp&lowbar;pass"> variables.

<p>Transport Encryption via the StartTLS command is also available. For
this to work, first of all Mutt-ng must be built with SSL or GNUTLS.
Secondly, the <ref id="smtp_use_tls"
name="&dollar;smtp&lowbar;use&lowbar;tls"> variable must be either set
to ``enabled'' or ``required.'' In both cases, StartTLS will be used if
the server supports it: for the second case, the connection will fail if
it doesn't while switching back to unencrypted communication for the
first one.

<p>Some mail providers require user's to set a particular envelope
sender, i.e. they allow for only one value which may not be what the
user wants to send as the <tt/From:/ header. In this case, the variable
<ref id="smtp_envelope" name="&dollar;smtp&lowbar;envelope"> may be used
to set the envelope different from the <tt/From:/ header.

<!-- }}} -->

<sect>Managing multiple IMAP/POP/NNTP accounts (OPTIONAL)<label id="account-hook"> <!--{{{--> 
<p>

If you happen to have accounts on multiple IMAP and/or POP servers,
you may find managing all the authentication settings inconvenient and
error-prone.  The account-hook command may help. This hook works like
folder-hook but is invoked whenever you access a remote mailbox
(including inside the folder browser), not just when you open the
mailbox.
<p>
Some examples:

<tscreen><verb>
account-hook . 'unset imap_user; unset imap_pass; unset tunnel'
account-hook imap://host1/ 'set imap_user=me1 imap_pass=foo'
account-hook imap://host2/ 'set tunnel="ssh host2 /usr/libexec/imapd"'
</verb></tscreen>

<!--}}}--> 

<sect>Start a WWW Browser on URLs (EXTERNAL)<label id="urlview"> <!--{{{--> 
<p>
If a message contains URLs (<em/unified resource locator/ = address in the
WWW space like <em>http://www.mutt.org/</em>), it is efficient to get
a menu with all the URLs and start a WWW browser on one of them.  This
functionality is provided by the external urlview program which can be
retrieved at <htmlurl url="ftp://ftp.mutt.org/mutt/contrib/"
name="ftp://ftp.mutt.org/mutt/contrib/"> and the configuration commands:
<tscreen><verb>
macro index \cb |urlview\n
macro pager \cb |urlview\n
</verb></tscreen>

<!--}}}--> 

<sect>Compressed folders Support (OPTIONAL) <!--{{{--> 
<p>

If Mutt-ng was compiled with compressed folders support (by running the
<em/configure/ script with the <em/--enable-compressed/ flag), Mutt
can open folders stored in an arbitrary format, provided that the user
has a script to convert from/to this format to one of the accepted.

The most common use is to open compressed archived folders e.g. with
gzip.

In addition, the user can provide a script that gets a folder in an
accepted format and appends its context to the folder in the
user-defined format, which may be faster than converting the entire
folder to the accepted format, appending to it and converting back to
the user-defined format.

There are three hooks defined (<ref id="open-hook" name="open-hook">,
<ref id="close-hook" name="close-hook"> and <ref id="append-hook"
name="append-hook">) which define commands to uncompress and compress
a folder and to append messages to an existing compressed folder 
respectively.

For example:

<tscreen><verb>
open-hook \\.gz$ "gzip -cd %f > %t" 
close-hook \\.gz$ "gzip -c %t > %f"
append-hook \\.gz$ "gzip -c %t >> %f" 
</verb></tscreen>

You do not have to specify all of the commands. If you omit <ref
id="append-hook" name="append-hook">, the folder will be open and
closed again each time you will add to it. If you omit <ref
id="close-hook" name="close-hook"> (or give empty command) , the
folder will be open in the  mode. If you specify <ref
id="append-hook" name="append-hook"> though you'll be able to append
to the folder.

Note that Mutt-ng will only try to use hooks if the file is not in one of
the accepted formats. In particular, if the file is empty, mutt
supposes it is not compressed. This is important because it allows the
use of programs that do not have well defined extensions. Just use
&dquot;.&dquot; as a regexp. But this may be surprising if your
compressing script produces empty files. In this situation, unset <ref
id="save_empty" name="&dollar;save&lowbar;empty">, so that the compressed file
will be removed if you delete all of the messages.

<sect1>Open a compressed mailbox for reading<label id="open-hook">
<p>
Usage: <tt/open-hook/ <em/regexp/ &dquot;<em/command/&dquot;

The <em/command/ is the command that can be used for opening the
folders whose names match <em/regexp/.

The <em/command/ string is the printf-like format string, and it
should accept two parameters: &percnt;f, which is replaced with the
(compressed) folder name, and &percnt;t which is replaced with the
name of the temporary folder to which to write.

&percnt;f and &percnt;t can be repeated any number of times in the
command string, and all of the entries are replaced with the
appropriate folder name. In addition, &percnt;&percnt; is replaced by
&percnt;, as in printf, and any other &percnt;anything is left as is.

The <em/command/ should <bf/not/ remove the original compressed file.
The <em/command/ should return non-zero exit status if it fails, so
mutt knows something's wrong.

Example:

<tscreen><verb>
open-hook \\.gz$ "gzip -cd %f > %t" 
</verb></tscreen>

If the <em/command/ is empty, this operation is disabled for this file
type.

<sect1>Write a compressed mailbox<label id="close-hook">
<p>
Usage: <tt/close-hook/ <em/regexp/ &dquot;<em/command/&dquot;

This is used to close the folder that was open with the <ref id="open-hook" 
name="open-hook"> command after some changes were made to it.

The <em/command/ string is the command that can be used for closing the
folders whose names match <em/regexp/. It has the same format as in 
the <ref id="open-hook" name="open-hook"> command. Temporary folder
in this case is the folder previously produced by the <<ref id="open-hook"
name="open-hook"> command.

The <em/command/ should <bf/not/ remove the decompressed file. The
<em/command/ should return non-zero exit status if it fails, so mutt
knows something's wrong.

Example:

<tscreen><verb>
close-hook \\.gz$ "gzip -c %t > %f"
</verb></tscreen>

If the <em/command/ is empty, this operation is disabled for this file
type, and the file can only be open in the readonly mode.

<ref id="close-hook" name ="close-hook"> is not called when you exit
from the folder if the folder was not changed.

<sect1>Append a message to a compressed mailbox<label id="append-hook">
<p>
Usage: <tt/append-hook/ <em/regexp/ &dquot;<em/command/&dquot;

This command is used for saving to an existing compressed folder.
The <em/command/ is the command that can be used for appending to the
folders whose names match <em/regexp/. It has the same format as in 
 the <ref id="open-hook" name="open-hook"> command.
The temporary folder in this case contains the messages that are being
appended. 

The <em/command/ should <bf/not/ remove the decompressed file. The
<em/command/ should return non-zero exit status if it fails, so mutt
knows something's wrong.

Example:

<tscreen><verb>
append-hook \\.gz$ "gzip -c %t >> %f" 
</verb></tscreen>

When <ref id="append-hook" name="append-hook"> is used, the folder is
not opened, which saves time, but this means that we can not find out
what the folder type is. Thus the default (<ref id="mbox_type"
name="&dollar;mbox&lowbar;type">) type is always supposed (i.e.
this is the format used for the temporary folder).

If the file does not exist when you save to it, <ref id="close-hook"
name="close-hook"> is called, and not <ref id="append-hook"
name="append-hook">. <ref id="append-hook" name="append-hook"> is only
for appending to existing folders.

If the <em/command/ is empty, this operation is disabled for this file
type. In this case, the folder will be open and closed again (using
<ref id="open-hook" name="open-hook"> and <ref id="close-hook" 
name="close-hook">respectively) each time you will add to it.

<sect1>Encrypted folders
<p>
The compressed folders support can also be used to handle encrypted
folders. If you want to encrypt a folder with PGP, you may want to use
the following hooks:

<tscreen><verb>
open-hook  \\.pgp$ "pgp -f < %f > %t"
close-hook \\.pgp$ "pgp -fe YourPgpUserIdOrKeyId < %t > %f"
</verb></tscreen>

Please note, that PGP does not support appending to an encrypted
folder, so there is no append-hook defined.

<bf/Note:/ the folder is temporary stored decrypted in the /tmp
directory, where it can be read by your system administrator. So think
about the security aspects of this.

<!--}}}--> 

<!--}}}--> 

<chapt>Mutt-ng's MIME Support <!--{{{--> 
<p>
Quite a bit of effort has been made to make Mutt-ng the premier text-mode
MIME MUA.  Every effort has been made to provide the functionality that
the discerning MIME user requires, and the conformance to the standards
wherever possible.  When configuring Mutt-ng for MIME, there are two extra
types of configuration files which Mutt-ng uses.  One is the
<tt/mime.types/ file, which contains the mapping of file extensions to 
IANA MIME types.  The other is the <tt/mailcap/ file, which specifies
the external commands to use for handling specific MIME types.

<sect>Using MIME in Mutt <!--{{{--> 
<p>
There are three areas/menus in Mutt-ng which deal with MIME, they are the
pager (while viewing a message), the attachment menu and the compose
menu.

<sect1>Viewing MIME messages in the pager
<p>
When you select a message from the index and view it in the pager, Mutt
decodes the message to a text representation.  Mutt-ng internally supports
a number of MIME types, including <tt>text/plain, text/enriched,
message/rfc822, and message/news</tt>.  In addition, the export
controlled version of Mutt-ng recognizes a variety of PGP MIME types,
including PGP/MIME and application/pgp.

Mutt-ng will denote attachments with a couple lines describing them.
These lines are of the form:
<tscreen><verb>
[-- Attachment #1: Description --]
[-- Type: text/plain, Encoding: 7bit, Size: 10000 --]
</verb></tscreen>
Where the <tt/Description/ is the description or filename given for the
attachment, and the <tt/Encoding/ is one of
<tt>7bit/8bit/quoted-printable/base64/binary</tt>.

If Mutt-ng cannot deal with a MIME type, it will display a message like:
<tscreen><verb>
[-- image/gif is unsupported (use 'v' to view this part) --]
</verb></tscreen>

<sect1>The Attachment Menu<label id="attach_menu">
<p>
The default binding for <tt/view-attachments/ is `v', which displays the
attachment menu for a message.  The attachment menu displays a list of
the attachments in a message.  From the attachment menu, you can save,
print, pipe, delete, and view attachments.  You can apply these
operations to a group of attachments at once, by tagging the attachments
and by using the ``tag-prefix'' operator.  You can also reply to the
current message from this menu, and only the current attachment (or the
attachments tagged) will be quoted in your reply.  You can view
attachments as text, or view them using the mailcap viewer definition.

Finally, you can apply the usual message-related functions (like 
<ref id="resend-message" name="resend-message">, and the reply
and forward functions) to attachments of type <tt>message/rfc822</tt>.

See the help on the attachment menu for more information.

<sect1>The Compose Menu<label id="compose_menu">
<p>
The compose menu is the menu you see before you send a message.  It
allows you to edit the recipient list, the subject, and other aspects
of your message.  It also contains a list of the attachments of your
message, including the main body.  From this menu, you can print, copy,
filter, pipe, edit, compose, review, and rename an attachment or a
list of tagged attachments.  You can also modifying the attachment
information, notably the type, encoding and description.

Attachments appear as follows:
<verb>
-   1 [text/plain, 7bit, 1K]             /tmp/mutt-euler-8082-0 <no description>
    2 [applica/x-gunzip, base64, 422K]   ~/src/mutt-0.85.tar.gz <no description>
</verb>

The '-' denotes that Mutt-ng will delete the file after sending (or
postponing, or canceling) the message.  It can be toggled with the
<tt/toggle-unlink/ command (default: u).  The next field is the MIME
content-type, and can be changed with the <tt/edit-type/ command
(default: ^T).  The next field is the encoding for the attachment,
which allows a binary message to be encoded for transmission on 7bit
links.  It can be changed with the <tt/edit-encoding/ command
(default: ^E).  The next field is the size of the attachment,
rounded to kilobytes or megabytes.  The next field is the filename,
which can be changed with the <tt/rename-file/ command (default: R).
The final field is the description of the attachment, and can be
changed with the <tt/edit-description/ command (default: d).

<!--}}}--> 

<sect>MIME Type configuration with <tt/mime.types/ <!--{{{--> 
<p>
When you add an attachment to your mail message, Mutt-ng searches your
personal mime.types file at <tt>&dollar;{HOME}/.mime.types</tt>, and then
the system mime.types file at <tt>/usr/local/share/mutt/mime.types</tt> or
<tt>/etc/mime.types</tt>

The mime.types file consist of lines containing a MIME type and a space
separated list of extensions.  For example:
<tscreen><verb>
application/postscript          ps eps
application/pgp                 pgp
audio/x-aiff                    aif aifc aiff
</verb></tscreen>
A sample <tt/mime.types/ file comes with the Mutt-ng distribution, and
should contain most of the MIME types you are likely to use.  

If Mutt-ng can not determine the mime type by the extension of the file you
attach, it will look at the file.  If the file is free of binary
information, Mutt-ng will assume that the file is plain text, and mark it
as <tt>text/plain</tt>.  If the file contains binary information, then Mutt-ng will
mark it as <tt>application/octet-stream</tt>.  You can change the MIME
type that Mutt-ng assigns to an attachment by using the <tt/edit-type/
command from the compose menu (default: ^T). The MIME type is actually a
major mime type followed by the sub-type, separated by a '/'. 6 major
types: application, text, image, video, audio, and model have been approved
after various internet discussions. Mutt-ng recognises all of these if the 
appropriate entry is found in the mime.types file. It also recognises other
major mime types, such as the chemical type that is widely used in the 
molecular modelling community to pass molecular data in various forms to 
various molecular viewers. Non-recognised mime types should only be used 
if the recipient of the message is likely to be expecting such attachments.

<!--}}}--> 

<sect>MIME Viewer configuration with <tt/mailcap/ <!--{{{--> 
<p>
Mutt-ng supports RFC 1524 MIME Configuration, in particular the Unix
specific format specified in Appendix A of RFC 1524.  This file format
is commonly referred to as the mailcap format.  Many MIME compliant
programs utilize the mailcap format, allowing you to specify handling
for all MIME types in one place for all programs.  Programs known to
use this format include Netscape, XMosaic, lynx and metamail.

In order to handle various MIME types that Mutt-ng can not handle
internally, Mutt-ng parses a series of external configuration files to
find an external handler.  The default search string for these files
is a colon delimited list set to
<tscreen><verb>
${HOME}/.mailcap:/usr/local/share/mutt/mailcap:/etc/mailcap:/etc/mailcap:/usr/etc/mailcap:/usr/local/etc/mailcap
</verb></tscreen>
where <tt/&dollar;HOME/ is your home directory.

In particular, the metamail distribution will install a mailcap file,
usually as <tt>/usr/local/etc/mailcap</tt>, which contains some baseline
entries.

<sect1>The Basics of the mailcap file
<p>
A mailcap file consists of a series of lines which are comments, blank,
or definitions.

A comment line consists of a &num; character followed by anything you want.

A blank line is blank.

A definition line consists of a content type, a view command, and any
number of optional fields.  Each field of a definition line is divided
by a semicolon ';' character.

The content type is specified in the MIME standard type/subtype method.
For example,
<tt>text/plain, text/html, image/gif, </tt>
etc.  In addition, the mailcap format includes two formats for
wildcards, one using the special '*' subtype, the other is the implicit
wild, where you only include the major type.  For example, <tt>image/*</tt>, or
<tt>video,</tt> will match all image types and video types,
respectively.

The view command is a Unix command for viewing the type specified. There
are two different types of commands supported. The default is to send
the body of the MIME message to the command on stdin. You can change
this behavior by using &percnt;s as a parameter to your view command.
This will cause Mutt-ng to save the body of the MIME message to a temporary
file, and then call the view command with the &percnt;s replaced by
the name of the temporary file. In both cases, Mutt-ng will turn over the
terminal to the view program until the program quits, at which time Mutt
will remove the temporary file if it exists.

So, in the simplest form, you can send a text/plain message to the
external pager more on stdin:
<tscreen><verb>
text/plain; more
</verb></tscreen>
Or, you could send the message as a file:
<tscreen><verb>
text/plain; more %s
</verb></tscreen>
Perhaps you would like to use lynx to interactively view a text/html 
message:
<tscreen><verb>
text/html; lynx %s
</verb></tscreen>
In this case, lynx does not support viewing a file from stdin, so you
must use the &percnt;s syntax.
<bf/Note:/ <em>Some older versions of lynx contain a bug where they
will check the mailcap file for a viewer for text/html.  They will find
the line which calls lynx, and run it.  This causes lynx to continuously
spawn itself to view the object.</em>

On the other hand, maybe you don't want to use lynx interactively, you
just want to have it convert the text/html to text/plain, then you can
use:
<tscreen><verb>
text/html; lynx -dump %s | more
</verb></tscreen>

Perhaps you wish to use lynx to view text/html files, and a pager on
all other text formats, then you would use the following:
<tscreen><verb>
text/html; lynx %s
text/*; more
</verb></tscreen>
This is the simplest form of a mailcap file.

<sect1>Secure use of mailcap
<p>
The interpretation of shell meta-characters embedded in MIME parameters
can lead to security problems in general.  Mutt-ng tries to quote parameters
in expansion of %s syntaxes properly, and avoids risky characters by
substituting them, see the <ref id="mailcap_sanitize"
name="mailcap&lowbar;sanitize"> variable.

Although mutt's procedures to invoke programs with mailcap seem to be
safe, there are other applications parsing mailcap, maybe taking less care
of it.  Therefore you should pay attention to the following rules:

<em/Keep the %-expandos away from shell quoting./
Don't quote them with single or double quotes.  Mutt-ng does this for
you, the right way, as should any other program which interprets
mailcap.  Don't put them into backtick expansions.  Be highly careful
with eval statements, and avoid them if possible at all.  Trying to fix
broken behaviour with quotes introduces new leaks - there is no
alternative to correct quoting in the first place.

If you have to use the %-expandos' values in context where you need
quoting or backtick expansions, put that value into a shell variable
and reference the shell variable where necessary, as in the following
example (using <tt/&dollar;charset/ inside the backtick expansion is safe,
since it is not itself subject to any further expansion):

<tscreen><verb>
text/test-mailcap-bug; cat %s; copiousoutput; test=charset=%{charset} \
        && test "`echo $charset | tr '[A-Z]' '[a-z]'`" != iso-8859-1
</verb></tscreen>

<sect1>Advanced mailcap Usage
<p>

<sect2>Optional Fields
<p>
In addition to the required content-type and view command fields, you
can add semi-colon ';' separated fields to set flags and other options.
Mutt-ng recognizes the following optional fields:
<descrip>
<tag/copiousoutput/
This flag tells Mutt-ng that the command passes possibly large amounts of
text on stdout.  This causes Mutt-ng to invoke a pager (either the internal
pager or the external pager defined by the pager variable) on the output
of the view command.  Without this flag, Mutt-ng assumes that the command
is interactive.  One could use this to replace the pipe to <tt>more</tt>
in the <tt>lynx -dump</tt> example in the Basic section:
<tscreen><verb>
text/html; lynx -dump %s ; copiousoutput
</verb></tscreen>
This will cause lynx to format the text/html output as text/plain
and Mutt-ng will use your standard pager to display the results.
<tag/needsterminal/
Mutt-ng uses this flag when viewing attachments with <ref id="auto_view"
name="autoview">, in order to decide whether it should honor the setting
of the <ref id="wait_key" name="&dollar;wait&lowbar;key"> variable or
not.  When an attachment is viewed using an interactive program, and the
corresponding mailcap entry has a <em/needsterminal/ flag, Mutt-ng will use
<ref id="wait_key" name="&dollar;wait&lowbar;key"> and the exit status
of the program to decide if it will ask you to press a key after the
external program has exited.  In all other situations it will not prompt
you for a key.
<tag>compose=&lt;command&gt;</tag>
This flag specifies the command to use to create a new attachment of a
specific MIME type.  Mutt-ng supports this from the compose menu.
<tag>composetyped=&lt;command&gt;</tag>
This flag specifies the command to use to create a new attachment of a
specific MIME type.  This command differs from the compose command in
that mutt will expect standard MIME headers on the data.  This can be
used to specify parameters, filename, description, etc. for a new
attachment.   Mutt-ng supports this from the compose menu.
<tag>print=&lt;command&gt;</tag>
This flag specifies the command to use to print a specific MIME type.
Mutt-ng supports this from the attachment and compose menus.
<tag>edit=&lt;command&gt;</tag>
This flag specifies the command to use to edit a specific MIME type.  
Mutt-ng supports this from the compose menu, and also uses it to compose
new attachments.  Mutt-ng will default to the defined editor for text
attachments.
<tag>nametemplate=&lt;template&gt;</tag>
This field specifies the format for the file denoted by &percnt;s in the
command fields.  Certain programs will require a certain file extension,
for instance, to correctly view a file.  For instance, lynx will only
interpret a file as <tt>text/html</tt> if the file ends in <tt/.html/.
So, you would specify lynx as a <tt>text/html</tt> viewer with a line in
the mailcap file like:
<tscreen><verb>
text/html; lynx %s; nametemplate=%s.html
</verb></tscreen>
<tag>test=&lt;command&gt;</tag>
This field specifies a command to run to test whether this mailcap
entry should be used.  The command is defined with the command expansion
rules defined in the next section.  If the command returns 0, then the
test passed, and Mutt-ng uses this entry.  If the command returns non-zero,
then the test failed, and Mutt-ng continues searching for the right entry.
<bf/Note:/ <em>the content-type must match before Mutt-ng performs the test.</em>
For example:
<tscreen><verb>
text/html; netscape -remote 'openURL(%s)' ; test=RunningX
text/html; lynx %s
</verb></tscreen>
In this example, Mutt-ng will run the program RunningX which will return 0
if the X Window manager is running, and non-zero if it isn't.  If
RunningX returns 0, then Mutt-ng will call netscape to display the
text/html object.  If RunningX doesn't return 0, then Mutt-ng will go on
to the next entry and use lynx to display the text/html object.
</descrip>

<sect2>Search Order
<p>
When searching for an entry in the mailcap file, Mutt-ng will search for
the most useful entry for its purpose.  For instance, if you are
attempting to print an <tt>image/gif</tt>, and you have the following
entries in your mailcap file, Mutt-ng will search for an entry with the
print command:
<tscreen><verb>
image/*;        xv %s
image/gif;      ; print= anytopnm %s | pnmtops | lpr; \
                nametemplate=%s.gif
</verb></tscreen>
Mutt-ng will skip the <tt>image/*</tt> entry and use the <tt>image/gif</tt>
entry with the print command.

In addition, you can use this with <ref id="auto_view" name="Autoview"> 
to denote two commands for viewing an attachment, one to be viewed
automatically, the other to be viewed interactively from the attachment
menu.  In addition, you can then use the test feature to determine which
viewer to use interactively depending on your environment.
<tscreen><verb>
text/html;      netscape -remote 'openURL(%s)' ; test=RunningX
text/html;      lynx %s; nametemplate=%s.html
text/html;      lynx -dump %s; nametemplate=%s.html; copiousoutput
</verb></tscreen>
For <ref id="auto_view" name="Autoview">, Mutt-ng will choose the third
entry because of the copiousoutput tag.  For interactive viewing, Mutt
will run the program RunningX to determine if it should use the first
entry.  If the program returns non-zero, Mutt-ng will use the second entry
for interactive viewing.

<sect2>Command Expansion
<p>
The various commands defined in the mailcap files are passed to the
<tt>/bin/sh</tt> shell using the system() function.  Before the
command is passed to <tt>/bin/sh -c</tt>, it is parsed to expand
various special parameters with information from Mutt-ng.  The keywords
Mutt-ng expands are:
<descrip>
<tag/&percnt;s/
As seen in the basic mailcap section, this variable is expanded
to a filename specified by the calling program.  This file contains
the body of the message to view/print/edit or where the composing
program should place the results of composition.  In addition, the
use of this keyword causes Mutt-ng to not pass the body of the message
to the view/print/edit program on stdin.
<tag/&percnt;t/
Mutt-ng will expand &percnt;t to the text representation of the content
type of the message in the same form as the first parameter of the
mailcap definition line, ie <tt>text/html</tt> or
<tt>image/gif</tt>.
<tag>&percnt;{&lt;parameter&gt;}</tag>
Mutt-ng will expand this to the value of the specified parameter
from the Content-Type: line of the mail message.  For instance, if
Your mail message contains:
<tscreen><verb>
Content-Type: text/plain; charset=iso-8859-1
</verb></tscreen>
then Mutt-ng will expand &percnt;{charset} to iso-8859-1.  The default metamail
mailcap file uses this feature to test the charset to spawn an xterm
using the right charset to view the message.
<tag>&bsol;&percnt;</tag>
This will be replaced by a &percnt;
</descrip>
Mutt-ng does not currently support the &percnt;F and &percnt;n keywords
specified in RFC 1524.  The main purpose of these parameters is for
multipart messages, which is handled internally by Mutt-ng.

<sect1>Example mailcap files
<p>
This mailcap file is fairly simple and standard:
<code>
# I'm always running X :)
video/*;        xanim %s > /dev/null
image/*;        xv %s > /dev/null

# I'm always running netscape (if my computer had more memory, maybe)
text/html;      netscape -remote 'openURL(%s)'
</code>

This mailcap file shows quite a number of examples:

<code>
# Use xanim to view all videos   Xanim produces a header on startup,
# send that to /dev/null so I don't see it
video/*;        xanim %s > /dev/null

# Send html to a running netscape by remote
text/html;      netscape -remote 'openURL(%s)'; test=RunningNetscape

# If I'm not running netscape but I am running X, start netscape on the
# object
text/html;      netscape %s; test=RunningX

# Else use lynx to view it as text
text/html;      lynx %s

# This version would convert the text/html to text/plain
text/html;      lynx -dump %s; copiousoutput

# I use enscript to print text in two columns to a page
text/*;         more %s; print=enscript -2Gr %s

# Netscape adds a flag to tell itself to view jpegs internally
image/jpeg;xv %s; x-mozilla-flags=internal

# Use xv to view images if I'm running X
# In addition, this uses the \ to extend the line and set my editor
# for images
image/*;xv %s; test=RunningX; \
        edit=xpaint %s

# Convert images to text using the netpbm tools
image/*;  (anytopnm %s | pnmscale -xysize 80 46 | ppmtopgm | pgmtopbm |
pbmtoascii -1x2 ) 2>&1 ; copiousoutput

# Send excel spreadsheets to my NT box
application/ms-excel; open.pl %s
</code>

<!--}}}--> 

<sect>MIME Autoview<label id="auto_view"> <!--{{{--> 
<p>
In addition to explicitly telling Mutt-ng to view an attachment with the
MIME viewer defined in the mailcap file, Mutt-ng has support for
automatically viewing MIME attachments while in the pager.

To work, you must define a viewer in the mailcap file which uses the 
<tt/copiousoutput/ option to denote that it is non-interactive.
Usually, you also use the entry to convert the attachment to a text
representation which you can view in the pager.

You then use the <tt/auto&lowbar;view/ muttrc command to list the
content-types that you wish to view automatically.

For instance, if you set auto&lowbar;view to:
<tscreen><verb>
auto_view text/html application/x-gunzip application/postscript image/gif application/x-tar-gz
</verb></tscreen>

Mutt-ng could use the following mailcap entries to automatically view
attachments of these types.
<tscreen><verb>
text/html;      lynx -dump %s; copiousoutput; nametemplate=%s.html
image/*;        anytopnm %s | pnmscale -xsize 80 -ysize 50 | ppmtopgm | pgmtopbm | pbmtoascii ; copiousoutput
application/x-gunzip;   gzcat; copiousoutput
application/x-tar-gz; gunzip -c %s | tar -tf - ; copiousoutput
application/postscript; ps2ascii %s; copiousoutput
</verb></tscreen>

``unauto_view'' can be used to remove previous entries from the autoview list.
This can be used with message-hook to autoview messages based on size, etc.
``unauto_view *'' will remove all previous entries.

<!--}}}--> 

<sect>MIME Multipart/Alternative<label id="alternative_order"> <!--{{{--> 
<p>
Mutt-ng has some heuristics for determining which attachment of a
multipart/alternative type to display.  First, mutt will check the 
alternative&lowbar;order list to determine if one of the available types
is preferred.  The alternative&lowbar;order list consists of a number of
MIME types in order, including support for implicit and explicit
wildcards, for example:
<tscreen><verb>
alternative_order text/enriched text/plain text application/postscript image/*
</verb></tscreen>

Next, mutt will check if any of the types have a defined 
<ref id="auto_view" name="auto&lowbar;view">, and use that.  Failing
that, Mutt-ng will look for any text type.  As a last attempt, mutt will
look for any type it knows how to handle.

To remove a MIME type from the <tt/alternative_order/ list, use the
<tt/unalternative_order/ command.

<!--}}}--> 

<sect>MIME Lookup<label id="mime_lookup"> <!--{{{--> 
<p>
Mutt-ng's mime&lowbar;lookup list specifies a list of mime-types that should not
be treated according to their mailcap entry.  This option is designed to
deal with binary types such as application/octet-stream.  When an attachment's
mime-type is listed in mime&lowbar;lookup, then the extension of the filename will
be compared to the list of extensions in the mime.types file.  The mime-type
associated with this extension will then be used to process the attachment
according to the rules in the mailcap file and according to any other configuration
options (such as auto&lowbar;view) specified.  Common usage would be:
<tscreen><verb>
mime_lookup application/octet-stream application/X-Lotus-Manuscript
</verb></tscreen>

In addition, the unmime&lowbar;lookup command may be used to disable this feature
for any particular mime-type if it had been set, for example, in a global
muttrc.

<!--}}}--> 

<!--}}}--> 

<chapt>Security Considerations <!--{{{--> 

  <p>First of all, mutt-ng contains no security holes included by
  intention but may contain unknown security holes. As a consequence,
  please run mutt-ng only with as few permissions as possible.

  <p>Please do not run mutt-ng as the super user.

  <p>When configuring mutt-ng, there're some points to note about secure
  setups.

  <p>In practice, mutt-ng can be easily made as vulnerable as even the
  most insecure mail user agents (in their default configuration) just
  by changing mutt-ng's configuration files: it then can execute
  arbitrary programs and scripts attached to messages, send out private
  data on its own, etc. Although this is not believed to the common type
  of setup, please read this chapter carefully.

  <sect>Passwords <!--{{{--> 

    <p>Although mutt-ng can be told the various passwords for accounts,
    please never store passwords in configuration files. Besides the
    fact that the system's operator can always read them, you could
    forget to replace the actual password with asterisks when reporting
    a bug or asking for help via, for example, a mailing list so that
    your mail including your password could be archived by internet
    search engines, etc. Please never store passwords on disk.

  <!--}}}-->

  <sect>Temporary Files <!--{{{--> 

    <p>Mutt-ng uses many temporary files for viewing messages, verifying
    digital signatures, etc. The <ref id="umask" name="&dollar;umask">
    variable can be used to change the default permissions of these
    files. Please only change it if you really know what you are doing.
    Also, a different location for these files may be desired which can
    be changed via the <ref id="tmpdir" name="&dollar;tmpdir"> variable.

  <!--}}}-->

  <sect>Information Leaks <!--{{{--> 

  <sect1>Message-ID: headers <!--{{{--> 

    <p>In the default configuration, mutt-ng will leak some information
    to the outside world when sending messages: the generation of
    <tt/Message-ID:/ headers includes a step counter which is increased
    (and rotated) with every message sent. If you'd like to hide this
    information probably telling others how many mail you sent in which
    time, you at least need to remove the <tt/%P/ expando from the
    default setting of the <ref id="msgid_format"
    name="&dollar;msgid&lowbar;format"> variable. Please make sure that
    you really know how local parts of these <tt/Message-ID:/ headers
    are composed.

  <!--}}}-->

  <sect1>mailto:-style links <!--{{{--> 

    <p>As mutt-ng be can be set up to be the mail client to handle
    <tt/mailto:/ style links in websites, there're security
    considerations, too. To keep the old behavior by default, mutt-ng
    will be strict in interpreting them which means that arbitrary
    header fields can be embedded in these links which could override
    existing header fields or attach arbitrary files. This may be
    problematic if the <ref id="edit_headers"
    name="&dollar;edit&lowbar;headers"> variable is <em/unset/, i.e. the
    user doesn't want to see header fields while editing the message.

    <p>For example, following a link like

    <verb>
mailto:joe@host?Attach=~/.gnupg/secring.gpg</verb>

    will send out the user's private gnupg keyring to <tt/joe@host/ if
    the user doesn't follow the information on screen carefully
    enough.

    <p>When <em/unsetting/ the <ref id="strict_mailto"
    name="&dollar;strict&lowbar;mailto"> variable, mutt-ng will

    <itemize>

      <item>be less strict when interpreting these links by
        prepending a <tt/X-Mailto-/ string to all header fields
        embedded in such a link <em/and/

      <item>turn on the <ref id="edit_headers"
        name="&dollar;edit&lowbar;headers"> variable by
        force to let the user see all the headers
        (because they still may leak information.)

    </itemize>

  <!--}}}-->

  <!--}}}-->

  <sect>External applications <!--{{{--> 

    <p>Mutt-ng in many places has to rely on external applications or
    for convenience supports mechanisms involving external
    applications.

    <sect1>mailcap <!--{{{--> 

      <p>One of these is the <tt/mailcap/ mechanism as defined by RfC
      1524. Mutt-ng can be set up to <em/automatically/ execute any
      given utility as listed in one of the mailcap files (see the
      <ref id="mailcap_path" name="&dollar;mailcap&lowbar;path">
      variable for details.) 

      These utilities may have a variety of security vulnerabilities,
      including overwriting of arbitrary files, information leaks or
      other exploitable bugs.  These vulnerabilities may go unnoticed by
      the user, especially when they are called automatically (and
      without interactive prompting) from the mailcap file(s). When
      using mutt-ng's autoview mechanism in combination with mailcap
      files, please be sure to...

      <itemize>

        <item>manually select trustworth applications with a reasonable
        calling sequence

        <item>periodically check the contents of mailcap files,
        especially after software installations or upgrades

        <item>keep the software packages referenced in the mailcap file up to date

        <item>leave the <ref id="mailcap_sanitize"
        name="&dollar;mailcap&lowbar;sanitize"> variable in its default
        state to restrict mailcap expandos to a safe set of characters

      </itemize>

    <!--}}}-->

    <sect1>Other <!--{{{--> 

      <p>Besides the mailcap mechanism, mutt-ng uses a number of other
      external utilities for operation.

      <p>The same security considerations apply for these as for tools
      involved via mailcap (for example, mutt-ng is vulnerable to Denial
      of Service Attacks with compressed folders support if the
      uncompressed mailbox is too large for the disk it is saved to.)

      <p>As already noted, most of these problems are not built in but
      caused by wrong configuration, so please check your configuration.

    <!--}}}-->

  <!--}}}-->

<!--}}}-->

<chapt>Reference <!--{{{--> 

<sect>Command line options<label id="commandline"> <!--{{{--> 
<p>
Running <tt/mutt/ with no arguments will make Mutt-ng attempt to read your spool
mailbox.  However, it is possible to read other mailboxes and
to send messages from the command line as well.

<tscreen><verb>
-A      expand an alias
-a      attach a file to a message
-b      specify a blind carbon-copy (BCC) address
-c      specify a carbon-copy (Cc) address
-e      specify a config command to be run after initialization files are read
-f      specify a mailbox to load
-F      specify an alternate file to read initialization commands
-h      print help on command line options
-H      specify a draft file from which to read a header and body
-i      specify a file to include in a message composition
-m      specify a default mailbox type
-n      do not read the system Muttngrc
-p      recall a postponed message
-Q      query a configuration variable
-R      open mailbox in read-only mode
-s      specify a subject (enclose in quotes if it contains spaces)
-t      dump the value of all variables to stdout
-T      dump the value of all changed variables to stdout
-v      show version number and compile-time definitions
-x      simulate the mailx(1) compose mode
-y      show a menu containing the files specified by the mailboxes command
-z      exit immediately if there are no messages in the mailbox
-Z      open the first folder with new message,exit immediately if none
</verb></tscreen>

To read messages in a mailbox

<tt/mutt/ &lsqb; -nz &rsqb; &lsqb; -F <em/muttrc/ &rsqb; &lsqb; -m <em/type/ &rsqb; &lsqb; -f <em/mailbox/ &rsqb; 

To compose a new message

<tt/mutt/ &lsqb; -n &rsqb; &lsqb; -F <em/muttrc/ &rsqb; &lsqb; -a <em/file/ &rsqb; &lsqb; -c <em/address/ &rsqb; &lsqb; -i <em/filename/ &rsqb; &lsqb; -s <em/subject/ &rsqb; <em/address/ &lsqb; <em/address/ ... &rsqb; 

Mutt-ng also supports a ``batch'' mode to send prepared messages.  Simply redirect
input from the file you wish to send.  For example,

<tt>mutt -s &dquot;data set for run &num;2&dquot; professor@bigschool.edu
&lt; &tilde;/run2.dat</tt>

This command will send a message to ``professor@bigschool.edu'' with a subject
of ``data set for run &num;2''.  In the body of the message will be the contents
of the file ``&tilde;/run2.dat''.

<!--}}}--> 

<sect>Patterns<label id="patterns"> <!--{{{--> 

<p>
<tscreen><verb>
~A              all messages
~b EXPR         messages which contain EXPR in the message body
~B EXPR         messages which contain EXPR in the whole message
~c USER         messages carbon-copied to USER
~C EXPR         message is either to: or cc: EXPR
~D              deleted messages
~d [MIN]-[MAX]  messages with ``date-sent'' in a Date range
~E              expired messages
~e EXPR         message which contains EXPR in the ``Sender'' field
~F              flagged messages
~f USER         messages originating from USER
~g              cryptographically signed messages
~G              cryptographically encrypted messages
~H EXPR         messages with a spam attribute matching EXPR
~h EXPR         messages which contain EXPR in the message header
~k              message contains PGP key material
~i ID           message which match ID in the ``Message-ID'' field
~L EXPR         message is either originated or received by EXPR
~l              message is addressed to a known mailing list
~m [MIN]-[MAX]  message in the range MIN to MAX *)
~M              multipart messages
~n [MIN]-[MAX]  messages with a score in the range MIN to MAX *)
~N              new messages
~O              old messages
~p              message is addressed to you (consults alternates)
~P              message is from you (consults alternates)
~Q              messages which have been replied to
~R              read messages
~r [MIN]-[MAX]  messages with ``date-received'' in a Date range
~S              superseded messages
~s SUBJECT      messages having SUBJECT in the ``Subject'' field.
~T              tagged messages
~t USER         messages addressed to USER
~U              unread messages
~v              message is part of a collapsed thread.
~V              cryptographically verified messages
~w EXPR         messages which contain EXPR in the `Newsgroups' field
                (if compiled with NNTP support)
~x EXPR         messages which contain EXPR in the `References' field
~y EXPR         messages which contain EXPR in the `X-Label' field
~z [MIN]-[MAX]  messages with a size in the range MIN to MAX *)
~=              duplicated messages (see $duplicate_threads)
~$              unreferenced messages (requires threaded view)
~*              ``From'' contains realname and (syntactically) valid
                address (excluded are addresses matching against
                alternates or any alias)
</verb></tscreen>

Where EXPR, USER, ID, and SUBJECT are 
<ref id="regexp" name="regular expressions">.  Special attention has to be
made when using regular expressions inside of patterns.  Specifically,
Mutt-ng's parser for these patterns will strip one level of backslash (\),
which is normally used for quoting.  If it is your intention to use a
backslash in the regular expression, you will need to use two backslashes
instead (\\).

*) The forms <tt/&lt;&lsqb;MAX&rsqb;/, <tt/&gt;&lsqb;MIN&rsqb;/,
<tt/&lsqb;MIN&rsqb;-/ and <tt/-&lsqb;MAX&rsqb;/
are allowed, too.

<!--}}}--> 

<sect>Configuration Commands<label id="commands"> <!--{{{--> 
<p>
The following are the commands understood by mutt.

<itemize>
<item>
<tt><ref id="account-hook" name="account-hook"></tt> <em/pattern/ <em/command/
<item>
<tt><ref id="alias" name="alias"></tt> <em/key/ <em/address/ &lsqb; , <em/address/, ... &rsqb;
<item>
<tt><ref id="alias" name="unalias"></tt> &lsqb; * | <em/key/ ... &rsqb;
<item>
<tt><ref id="alternates" name="alternates"></tt> <em/regexp/ &lsqb; <em/regexp/ ... &rsqb;
<item>
<tt><ref id="alternates" name="unalternates"></tt> &lsqb; * | <em/regexp/ ... &rsqb;
<item>
<tt><ref id="alternative_order" name="alternative&lowbar;order"></tt> <em/mimetype/ &lsqb; <em/mimetype/ ... &rsqb;
<item>
<tt><ref id="alternative_order" name="unalternative&lowbar;order"></tt> <em/mimetype/ &lsqb; <em/mimetype/ ... &rsqb;
<item>
<tt><ref id="append-hook" name="append-hook"></tt> <em/regexp/ <em/command/
<item>
<tt><ref id="auto_view" name="auto&lowbar;view"></tt> <em/mimetype/ &lsqb; <em/mimetype/ ... &rsqb;
<item>
<tt><ref id="auto_view" name="unauto&lowbar;view"></tt> <em/mimetype/ &lsqb; <em/mimetype/ ... &rsqb;
<item>
<tt><ref id="bind" name="bind"></tt> <em/map/ <em/key/ <em/function/
<item>
<tt><ref id="charset-hook" name="charset-hook"></tt> <em/alias/ <em/charset/
<item>
<tt><ref id="close-hook" name="close-hook"></tt> <em/regexp/ <em/command/
<item>
<tt><ref id="color" name="color"></tt> <em/object/ <em/foreground/ <em/background/ &lsqb; <em/regexp/ &rsqb;
<item>
<tt><ref id="color" name="uncolor"></tt> <em/index/ <em/pattern/ &lsqb; <em/pattern/ ... &rsqb;
<item>
<tt><ref id="exec" name="exec"></tt> <em/function/ &lsqb; <em/function/ ... &rsqb;
<item>
<tt><ref id="fcc-hook" name="fcc-hook"></tt> <em/pattern/ <em/mailbox/
<item>
<tt><ref id="fcc-save-hook" name="fcc-save-hook"></tt> <em/pattern/ <em/mailbox/
<item>
<tt><ref id="folder-hook" name="folder-hook"></tt> <em/pattern/ <em/command/
<item>
<tt><ref id="hdr_order" name="hdr&lowbar;order"></tt> <em/header/ &lsqb; <em/header/ ... &rsqb;
<item>
<tt><ref id="hdr_order" name="unhdr&lowbar;order"></tt> <em/header/ &lsqb; <em/header/ ... &rsqb;
<item>
<tt><ref id="charset-hook" name="iconv-hook"></tt> <em/charset/ <em/local-charset/
<item>
<tt><ref id="ignore" name="ignore"></tt> <em/pattern/ &lsqb; <em/pattern/ ... &rsqb;
<item>
<tt><ref id="ignore" name="unignore"></tt> <em/pattern/ &lsqb; <em/pattern/ ... &rsqb;
<item>
<tt><ref id="lists" name="lists"></tt> <em/regexp/ &lsqb; <em/regexp/ ... &rsqb; 
<item>
<tt><ref id="lists" name="unlists"></tt> <em/regexp/ &lsqb; <em/regexp/ ... &rsqb; 
<item>
<tt><ref id="macro" name="macro"></tt> <em/menu/ <em/key/ <em/sequence/ &lsqb; <em/description/ &rsqb; 
<item>
<tt><ref id="mailboxes" name="mailboxes"></tt> <em/filename/ &lsqb; <em/filename/ ... &rsqb;
<item>
<tt><ref id="mbox-hook" name="mbox-hook"></tt> <em/pattern/ <em/mailbox/
<item>
<tt><ref id="message-hook" name="message-hook"></tt> <em/pattern/ <em/command/
<item>
<tt><ref id="mime_lookup" name="mime&lowbar;lookup"></tt> <em/mimetype/ &lsqb; <em/mimetype/ ... &rsqb;
<item>
<tt><ref id="mime_lookup" name="unmime&lowbar;lookup"></tt> <em/mimetype/ &lsqb; <em/mimetype/ ... &rsqb;
<item>
<tt><ref id="color" name="mono"></tt> <em/object attribute/ &lsqb; <em/regexp/ &rsqb;
<item>
<tt><ref id="color" name="unmono"></tt> <em/index/ <em/pattern/ &lsqb; <em/pattern/ ... &rsqb;
<item>
<tt><ref id="my_hdr" name="my&lowbar;hdr"></tt> <em/string/
<item>
<tt><ref id="my_hdr" name="unmy&lowbar;hdr"></tt> <em/field/ &lsqb; <em/field/ ... &rsqb;
<item>
<tt><ref id="open-hook" name="open-hook"></tt> <em/regexp/ <em/command/
<item>
<tt><ref id="crypt-hook" name="crypt-hook"></tt> <em/pattern/ <em/key-id/
<item>
<tt><ref id="push" name="push"></tt> <em/string/
<item>
<tt><ref id="set" name="reset"></tt> <em/variable/ &lsqb;<em/variable/ ... &rsqb;
<item>
<tt><ref id="save-hook" name="save-hook"></tt> <em/regexp/ <em/filename/
<item>
<tt><ref id="score-command" name="score"></tt> <em/pattern/ <em/value/
<item>
<tt><ref id="score-command" name="unscore"></tt> <em/pattern/ &lsqb; <em/pattern/ ... &rsqb;
<item>
<tt><ref id="send-hook" name="send-hook"></tt> <em/regexp/ <em/command/
<item>
<tt><ref id="reply-hook" name="reply-hook"></tt> <em/regexp/ <em/command/
<item>
<tt><ref id="set" name="set"></tt> &lsqb;no|inv&rsqb;<em/variable/&lsqb;=<em/value/&rsqb; &lsqb; <em/variable/ ... &rsqb;
<item>
<tt><ref id="set" name="unset"></tt> <em/variable/ &lsqb;<em/variable/ ... &rsqb;
<item>
<tt><ref id="source" name="source"></tt> <em/filename/
<item>
<tt><ref id="spam" name="spam"></tt> <em/pattern/ <em/format/
<item>
<tt><ref id="spam" name="nospam"></tt> <em/pattern/
<item>
<tt><ref id="lists" name="subscribe"></tt> <em/regexp/ &lsqb; <em/regexp/ ... &rsqb; 
<item>
<tt><ref id="lists" name="unsubscribe"></tt> <em/regexp/ &lsqb; <em/regexp/ ... &rsqb; 
<item>
<tt><ref id="set" name="toggle"></tt> <em/variable/ &lsqb;<em/variable/ ... &rsqb;
<item>
<tt><ref id="unhook" name="unhook"></tt> <em/hook-type/
</itemize>

<sect>Configuration variables<label id="variables">

<p>The following list contains all variables which, in the process of
providing more consistency, have been renamed and are partially even
removed already. The left column contains the old synonym variables,
the right column the full/new name:

<label id="sect_obsolete">
<tscreen><verb>
edit_hdrs               edit_headers
forw_decode             forward_decode
forw_format             forward_format
forw_quote              forward_quote
hdr_format              index_format
indent_str              indent_string
mime_fwd                mime_forward
msg_format              message_format
pgp_autosign            crypt_autosign
pgp_autoencrypt         crypt_autoencrypt
pgp_replyencrypt        crypt_replyencrypt
pgp_replysign           crypt_replysign
pgp_replysignencrypted  crypt_replysignencrypted
pgp_verify_sig          crypt_verify_sig
pgp_create_traditional  pgp_autoinline
pgp_auto_traditional    pgp_replyinline
forw_decrypt            forward_decrypt
smime_sign_as           smime_default_key
post_indent_str         post_indent_string
print_cmd               print_command
shorten_hierarchy       sidebar_shorten_hierarchy
ask_followup_to         nntp_ask_followup_to
ask_x_comment_to        nntp_ask_x_comment_to
catchup_newsgroup       nntp_catchup
followup_to_poster      nntp_followup_to_poster
group_index_format      nntp_group_index_format
inews                   nntp_inews
mime_subject            nntp_mime_subject
news_cache_dir          nntp_cache_dir
news_server             nntp_host
newsrc                  nntp_newsrc
nntp_poll               nntp_mail_check
pop_checkinterval       pop_mail_check
post_moderated          nntp_post_moderated
save_unsubscribed       nntp_save_unsubscribed
show_new_news           nntp_show_new_news
show_only_unread        nntp_show_only_unread
x_comment_to            nntp_x_comment_to
smtp_auth_username      smtp_user
smtp_auth_password      smtp_pass
</verb></tscreen>

The <tt/contrib/ subdirectory contains a script named
<tt/update-config.pl/ which eases migration.

A complete list of current variables follows.

<p>