I'm not sure I'd use it as a daily mail client or anything but the UNIX mail client is pretty functional. If nothing else being able to type "d 1-(number of mail messages)" whenever a cron job goes ballistic is really handy.
@craigmaloney I lived in elm and then mutt forever, but HTML email is 90% these days, so I gave up.
@craigmaloney Agree. Also, edmail on Plan 9 extends that nicely so you can select ranges using an ed-like syntax. It's my go-to cleanup tool.