Rated 5 out of 5 stars

Από τον/την Jin-Hong Shin στις Αύγ. 6, 2008 · μόνιμος σύνδεσμος

Now it freezes no more! I don't know what has made it. Maybe due to newer version of Thunderbird, as this add-on has not been updated for long.
Anyway now it works great. I hope the mozilla guys integrate this functionality into the next version.