Rated 5 out of 5 stars

Doesn't work in thunderbird 60.2.1
Hope this will be fix!

PS. This bug is always fixed in version 1.4.6
You can download it from github

Great work, Ysard!

This review is for a previous version of the add-on (1.4.4). 

Hi, thanks for the review;
the addon has been tested successfully on TB 60.2.1; what is your operating system?
Maybe this your problem is related to this issue that is still annoying at the moment: