Rated 5 out of 5 stars

It's funny, on this page you see "Version 1.2.13
* Fixed compatibility with Thunderbird 7", but only version 1.2.12 can be downloaded. And then, on http://lookout.mozdev.org/installation.html , you can download version 1.2.3, but it doesn't work either on TB 7.x. :-(

This review is for a previous version of the add-on (1.2.12). 

If you want to get it before mozilla approves it then click the link that says "see version history" or use this link
https://addons.mozilla.org/en-US/thunderbird/addon/lookout/versions/