Rated 3 out of 5 stars

It finds dupes and is fast about doing so, but the documentation is almost nonexistent. It is impossible to toggle a message between keep and delete In Windows 7 / TB 31.2.0 / add on version 0.1.14 .

There is no support channel and the add on doesn't play nice with Thunderbird.

If all your messages are in one big folder and you want to run something once to clean up dupes then this will work for you. Otherwise it is of limited use.