Review for Remove Duplicate Messages by jak
Rated 5 out of 5 stars
I had a problem scanning my mails in different accounts (xxx@free.fr and yyy@free.fr). The solution is to select one account and then CTRL + mouse click on the second account (or/ and third...). It finds the emails that were sent to both accounts.
Thanks a lot for this extension which saves a lot of time and seems to be quite safe for the user. Sorry I had to give it a bad appreciation before to get in touch with Eyal Rosenberg. I'll try to remove it.
To create your own collections, you must have a Mozilla Add-ons account.