Imap could use an "outbox". Not just a mua outbox queuing up all the mail 'till a connection is made, no, a real outbox. The mail client sends outgoing mail to the outbox on the imap server, wich hands it to the smtp server.

##NAME: OUTBOX:0 # # The next set of options deal with the "Outbox" enhancement. # Uncomment the following setting to create a special folder, named # INBOX.Outbox # # OUTBOX=.Outbox

##NAME: SENDMAIL:0 # # If OUTBOX is defined, mail can be sent via the IMAP connection by copying # a message to the INBOX.Outbox folder. For all practical matters, # INBOX.Outbox looks and behaves just like any other IMAP folder. If this # folder doesn't exist it must be created by the IMAP mail client, just # like any other IMAP folder. The kicker: any message copied or moved to # this folder is will be E-mailed by the Courier-IMAP server, by running # the SENDMAIL program. [...]