Rated 5 out of 5 stars

Very stable and very useful. Should have been a standard feature of Thunderbird. I use multiple IMAP accounts and it works well: is configurable enough and not a resource hog. I can always see just how close I'm getting to the quota limits -- and it works correctly with accounts that have NO quota.

This review is for a previous version of the add-on (0.2.1.1).