I really like mail (in panther), because its main view amalgamates all my different pop/imap accounts in one view, and the rules let me sort out common mails (like mailing lists) into other folders.

ONE feature that's missing, which I think they should have added, is a way to view all 'flagged' mails in any folder, in one list. That way, I can keep anything I think was very important in one folder, kinda like gmail's 'starred' messages.

But I guess now that Tiger and mail 2.0's out, I won't see my wish granted. :(

I'd like to migrate to thunderbird, but it didn't amalgamate my different mail accounts into 1 list (yet keep them separate at the same time), and there's no 'nice' importer for mail->Tbird.