Rated 4 out of 5 stars

Really nice addon, unfortunatelly not compatible with new thunderbird..
Please, update? :o)

This review is for a previous version of the add-on (4.4.1). 

The latest verion 5.0.2 was released on December 2nd and is fully compatible with Thunderbird 78.

It takes a lot of time and quite a bit of money, so if you want to support that financially, check out the support pages. here is the issue that handles the upgrade:
if you comment there you will be the first to be notified of a beta version!