Review for Folderpane Tools by chuckLP
Rated 5 out of 5 stars
Folderpane Tools is a very useful add-on. I really like it. Finally, I can arrange my accounts in the folder pane in a sequence that makes sense to me.
I agree with the others: This should standard functionality in Thunderbird.
To create your own collections, you must have a Mozilla Add-ons account.