Rated 5 out of 5 stars

I've been using this MailClassifier for 6 months now to sort all my email.

It's accurate for 9/10 emails and integrates seamlessly with Thunderbird.

It uses less resources than PopFile, and does not slow down after months of training (unlike my PopFile experience)
Supports POP3 and IMAP seamlessly - something PopFile requires plug-ins for.

I still use the Thunderbird built-in classification for Spam though.

This review is for a previous version of the add-on (1.0).