Check out tinymail[1]. This guy took a pretty cerebral approach to developing his MUA back-end library. I've used it in the form of Modest[2] on my Nokia n810.
Personally, I'd hate to see any more dev hours wasted on garbage like imap or pop3. ssh/rsyncing maildir to form a 'local copy,' then 'commiting' changes back seems much saner to me. [1] - http://tinymail.org/ [2] - http://modest.garage.maemo.org/ -- # Kurt H Maier
