Review for Manually sort folders by Frank Thomas
Rated 5 out of 5 stars
For some Extensions it only takes a second to know that it is a "why didn't Mozilla add this" Extension. This is one.
Only dealing with two Profiles, but being able to move Folders shortens mouse distance. That make dragging a message from Folder to Folder that much easier.
To create your own collections, you must have a Mozilla Add-ons account.