Rated 5 out of 5 stars

by beached on Sept. 26, 2017 ·

I just downloaded this and used it to fix a large Sent folder and another Sent subfolder which had been corrupted with duplicates and was slowing Thunderbird. As long as you don't overwhelm the Remove Dup Messages add-on with a huge number of sets (duplicates) it is great and reliable.
I found that it still worked on 40,000 messages with 14,000 duplicate sets.
Great Add-on

This review is for a previous version of the add-on (0.3.14). 

by Eyal Rozenberg (Developer) on Sept. 26, 2017 ·

I've tested the extension with over 90,000 messages, but not as many dupe sets as you had. Good to know :-)

Also - readers should be reminded that if you include message bodies as a comparison criteria the extension would be much slower (although it should still get through them eventually).