Rated 3 out of 5 stars

I far prefer this extension to the other (more updated) remove duplicates addon. Better features and implementation.

Unfortunately though, due to it being two years since its last update, Remove Duplicate Messages (Alternate) 0.3.7 doesn't work 100% properly with the current release Thunderbird 17.0.6 (US English).

Do a scan for duplicates (including message bodies) on a large inbox of a POP mail account. Have the add-on set to show you a new window with a list of proposed message to keep & delete after a scan. Have it set to to "Trash" folder (which exists on that POP account).

Execute it and delete the checkmarked messages. Problem: they don't appear in that account's Trash folder. Not after doing the deletion and not after restarting Thunderbird. The duplicates are wrongly permanently deleted, even though you set the addon to move them to the Trash folder.

Oh well. As it looks like this add-on isn't going to be updated (but I hope it will be), users should be aware of this problem.

This review is for a previous version of the add-on (0.3.7).