Rated 4 out of 5 stars

I like this add-on very much because I store all my sent and received e-mails in the same folder to get an overview on complete message threads (including my replies).
Unfortunately, the iconic graphic on the "incoming/outgoing" column increases the height of the whole header bar a few pixels on Windows (XP or Vista w/ classic theme). I have to replace the graphic everytime this add-on is updated.

This review is for a previous version of the add-on (0.5.12).