Bah. What's a good alternative native email reader?
KMail / Kontact is actually a very nice client / integrated suite (and it will happily play either way). I consider it the best general PIM I've encountered on any platform.
Balsa and Thunderbird (GNOME).
Note: No built-in IMAP (use fetchmail). Uses Xapian for searching. Handles multiple SMTP servers well (unlike TBird)
From what I recall and read: sup is the ruby-based implementation of mutt. I believe there are also forks of the mainstream mutt which incorporate indexing, tags, and notmuch.
In seriousness, I'm not sure there is one.
[1]: http://www.techradar.com/news/software/applications/best-lin...