bcc
binary
cc
+compose
+composetyped
content-description
content-disposition
content-length
content-transfer-encoding
content-type
+copiousoutput
date
digest
+edit
expires
external-body
followup-to
from
image
in-reply-to
-news
-rfc822
iso-2022-jp
lines
list-post
mime-version
model
multipart
+nametemplate
+needsterminal
+news
newsgroups
organization
+print
quoted-printable
received
references
reply-to
return-path
+rfc822
sender
status
subject
supercedes
supersedes
+test
text
to
unknown
utf-8
video
x-comment-to
+x-convert
x-label
xref
x-status