I feel awkward admitting that I don’t use primarily mutt as my mail client (I do use it when I ssh into various machines), but I’m a big fan of KMail.
I’ve never found a perfect mail client, but I’ve used KMail off and on as my primary client since 2000, and it’s definitely my favorite.
I strongly prefer IMAP, and only two clients I’ve tried have handled IMAP at all decently: Mail.app on Mac OS X (just about the only Mac OS X application I might reasonably miss) and KMail. My most recent flirtation was with Evolution, but as my mail folders grew larger and more numerous, its performance went from adequate to abysmal and, finally, unusable.
When I switched back to KMail, I set up my IMAP connections as cached IMAP connections, and my problems went away.
I have a few small gripes and questions that I really should ask on a #kmail or #kontact IRC channel sometime, but it’s only when something goes seriously weird that I even have to think about my mail program. That’s the sign of a quality program.
Thank you to all KMail and Kontact contributors and developers!
I've been impressed with the test releases of Thunderbird 2. Interface remains responsive while waiting on servers. Doesn't sound like my imap collection is as large as yours though.
I, too, use KMail as my primary email client in a KDE environment.
I used to use Thunderbird but there was just something about it which didn't feel right. Perhaps it will be "fixed" in Thunderbird 2.0.
In any case, KMail is great.
I used to use KMail, but it crashed too often (which I didn't care about) and often took my mail with it (which I did care about). I had problems with IMAP also. I started using Thunderbird and haven't looked back...plus its cross-platform so I can use it on my Windows and BSD machines at work, and at home on my Linux machine. I use IMAP exclusively now with a number of accounts, my work account has 50+ mailboxes with tens of thousands of messages (over 900 MB) total, some single mailboxes with sometimes over 10k (I get lazy with mailing lists) and it very rarely has any problems; none that cause data loss. Plus it integrates with remote ical and gpg easily.
What about Thunderbird?
I have never used a more stable IMAP client than thunderbird. Even though i use Mail.app now a days...
Cheers!
Claws Mail (nee Sylpheed Claws) is a great mail client for techies. It works for non-techies too, of course, but its quick search bar, extensive filtering and powerful processing (even an in-built perl processor if you want) make it great for technical people. Full of simple but useful features - for example, when replying to a mail, select the text you want to quote, hit 'reply', and the compose window has only the text you selected in it.
Does KMail handle filtering on IMAP yet? Last I checked, it didn't, but that was some time ago. And of course I'm biased in favor of Evolution... have you tried that one?
Oh, sorry, I missed that sentence; you did. Performance trouble on large folders? Really? I never had that problem!
Hmmm I will have to look into kmail, but I would argue there are alot of great apps on OS X.
Just my two cents