Fetchmail will serve as a retrieval agent with IMAP servers. FetchmailQuote:
> Can someone help me with a MS Exchange client for Linux.
> I can't read my mail with pop because that's disable on the mail server.
is not strictly a client or an MTA,but an intermediate utility. You
still need sendmail, qmail, or such, and a client program like pine,
mutt, Xmh, etc.