Review for Remove Duplicate Messages by Luc Bougé
Rated 5 out of 5 stars
Very useful tool. Thanks!
One detail: the selection dialog proposes to move the deleted copies to Trash. However, I am using several accounts, and therefore several disctinct Trash folders. I was surprised to find al the deleted copies in the Trash of my Local Folders. Is it normal?
To create your own collections, you must have a Mozilla Add-ons account.