Rated 3 out of 5 stars

This add-on needs to "Have full, unrestricted access to Thunderbird, and your computer". I think this is a big ask considering what is expected of this app. Would have rated it 5 stars if it weren't for that.

This review is for a previous version of the add-on (5.10). 

There is ongoing effort to remove that full-access-permission:
https://github.com/jobisoft/quicktext/issues/371