Great! Rated 5 out of 5 stars

This extension greatly improves the workflow of using Thunderbird. E-mails can be filed automatically in the correct folders, but it's not like a filter, so you can see it in the inbox first, and then press Shift-S to file it away. The folder name completion is great, and the fact that you can just press a few keys to manually file messages in folders.

This review is for a previous version of the add-on (0.2.2).