Works like a charm! (pre.: Reply-all broken) Rated 5 out of 5 stars

The extension isn't broken after all. It appeared to be an other extension which makes reply-all behave incorrectly... Granted this on the 5 stars it deserves...

<i>Original review:</i>
I've been a users of this plugin for a long time and would have rated it 5 stars (sorry for not effectively doing that). But as of version 13 of Thunderbird (running on Ubuntu), reply-all is broken...

This review is for a previous version of the add-on (2.0.6). 

Could you please try "restore default set" and then add the reply all button again. I am not sure but this might be some upgrade related problem.