MUA from Emacs with convinces for mail threads?

[Oleksandr Gavenko]

I look for MUA from Emacs.

I have experience with Thunderbird but it is look monstrous and
VERY slow.

I need thread support and cross platform solution (ever through Cygwin
if it is easily). NNTP/POP/IMAP/SMTP.

But thing that stop me from using Thunderbird is imposibility
mark thread that I started or in which I replay-to and
specially notify me for replays to this thread.

When you subscribed to tech mail/news list it is good to be especially
notified when someone answered in thread for which you involved in
discussion because of hi count of incoming mails!

Also it is good if MUA fix broken threads (by subject similarity/date).

If anyone know non-Emacs solution it is also be helpful.