Rated 5 out of 5 stars
Exactly what I needed. Thunderbird kept slowing to a crawl because one of my Linux newsgroups kept reverting to 61,000 (or so) messages unread. I'm not sure which feature of ThunderPlunger did the job ("Remove Phantom Messages" or "Clear All Expired") because I tried both -- but now the problem is completely cleared. I haven't checked out all of ThunderPlunger's features, but it's definitely worth installing, just for the two mentioned. Thanks!This review is for a previous version of the add-on (1.2).