Use the better alternative to this extension! Rated 1 out of 5 stars

This extension has been effectively abandoned by its author for almost 2 years, without significant updates. It is also not free software, so the code cannot be used elsewhere.

For this reason I have fully rewritten a dupe removal extension of my own, which is actually free software:

Remove Duplicate Messages (alternate)

It has seen more active development, has a richer feature set (which proerly includes the features of this extension) and for which issues can be opened on Mozdev's bugzilla and addressed within a reasonable amount of time.

This review is for a previous version of the add-on (0.1.02).