Review for Remove Duplicate Messages by Peter.Fairchild
Rated 4 out of 5 stars
I used this add-on and liked the way it presented the duplicates. If there are more than two, you see them all and can choose which one to keep. The default has always been correct
This review is for a previous version of the add-on (0.1.4).To create your own collections, you must have a Mozilla Add-ons account.