imap-message-append

imap-message-append is a compiled Lisp function in `imap.el'.

(imap-message-append MAILBOX ARTICLE &optional FLAGS DATE-TIME BUFFER)

Append ARTICLE (a buffer) to MAILBOX on server in BUFFER.
FLAGS and DATE-TIME is currently not used. Return a cons holding
uidvalidity of MAILBOX and UID the newly created article got, or nil
on failure.