int pop_connect (POP_DATA *);
pop_query_status pop_open_connection (POP_DATA *);
pop_query_status pop_query_d (POP_DATA *, char *, size_t, char *);
int pop_connect (POP_DATA *);
pop_query_status pop_open_connection (POP_DATA *);
pop_query_status pop_query_d (POP_DATA *, char *, size_t, char *);