Rated 4 out of 5 stars

Nearly really really good...
Simple to run (just select the option on right-click menu (windows)) - and very clear interface. Ran it on an IMAP inbox -it found and removed 419 dupes - great; but it missed another dozen. Why?? Still, the 419 saved a lot of mouse finger strain! - Thanks
(Using TB 3.0.3)

This review is for a previous version of the add-on (0.3.3). 

removedupes didn't miss anything; the other messages were simply not exact dupes, only similar. Try relaxing your comparison criteria.