Rated 4 out of 5 stars

Bummer the extension hasn't been updated for Tbird 2.0. I hacked the current extension and made it work but it is offered *as is*, with no absolutely no warranty that it works correctly.

http://bohnfamily.com/xpi/remove_duplicate_messages-0.1.01-mb.xpi

Mike

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