Worked great Rated 5 out of 5 stars

Worked like a charm whereas the "(alternate)" version (found here: https://addons.mozilla.org/en-US/thunderbird/addon/remove-duplicate-messages-alte/?src=search) was too strict in it's analysis, and wouldn't find any "non-identical" duplicates. By non-identical, I mean that I imported some messages from outlook to thunderbird, and somehow the duplicates were very slightly different (maybe a header? or an extra new-line in the message?). Anyway, you can see how I imported from Outlook here (http://forums.mozillazine.org/viewtopic.php?f=39&t=2564993)