Review for ThreadVis by pzYsTorM
Rated 3 out of 5 stars
Nice addon. But some annoying bugs:
When moving a mail to other imap folders, the cache does not update.
Or with new mails (imap), too.
I have no pop3 mail accounts. Dont know if its working there.
To create your own collections, you must have a Mozilla Add-ons account.