Rated 5 out of 5 stars

per WillyP el jul. 29, 2011 ·

Works great, you can right click and choose to add your siggy at the cursor or at the end of the e-mail.
Took me a little head scratching to figure out how to set up a signature, here are the instructions: Signatures | How to | Thunderbird - http://support.mozillamessaging.com/en-US/kb/signatures

This review is for a previous version of the add-on (0.2).