Rated 4 out of 5 stars

Unfortunately checkboxes for keeping messages still don't show up in the newest 0.61 version with my Thunderbird version of 52.8.
Otherwise it seems to work fine - finds duplicates across many folders.
A fix would be great, because now I have to delete the found copies manually in the folders.

This review is for a previous version of the add-on (0.3.16).