Rated 3 out of 5 stars

Does not seem to work in Thunderbird(3.0.4 Windows XP) even after many restarts.

Appears to work fine for Firefox(3.6.3 Windows XP)

This review is for a previous version of the add-on (1.0.2). 

Very subtle in TB

Very few tweaks to Thunderbird - they're more subtle. This add-on is (currently) more focused on Firefox.