Rated 5 out of 5 stars

It works on TB 78.7.1 _IF_ the settings are right.
Go to Extra->AddOnSettings->RemoveDuplicate

In the right panel (comparison settings) i had to set:
- compare adresses
- From
- To
- CC to
- Status
- Message ID
- Number of lines
- time of sending
- Subject
- Message Text

Unset:
- size
- folders

Comparison time: Minutes
(Items Translated from the German version)

Would be nice if the add on would have a basic working setup.

This review is for a previous version of the add-on (0.5.1b2).