Here's an thread talking about how stupid uw-imapd is (it seems pretty universally disliked, though most other imapds don't have much of a better reputation). This thread is noteworthy in that both the ex-maintainer and current maintainer of uw-imapd for Debian say that DoveCot, which I had never heard of before, is "the future".
Mail is such a huge mess. A school friend started sending me PGP'd messages just to be cute, but apparently pine and mutt disagree on how the messages should be sent (pine: text/plain, with BEGIN PGP blah blah delimiters; mutt: mime parts with application/pgp content-types). I guess everyone just procmails around it? Feh. Why am I wasting my life learning about this?