I've never really cared for pine, mutt handles threads and massive mailboxes much better. Plus it's the most standards-compliant email reader on the planet. (according to mutt afficionados) But firing up mutt the first time presents you with a pretty ugly worldview. You need to know how to cobble together a .muttrc. I have one that works very well for me, if somebody wants it, I'll mail it to you.