Rated 3 out of 5 stars

Dear Andreas,
I've found a bug that prevents me to enjoy this extension.
Stats tabs does not display any results and I think that I have found the reason using the thnderbird built-in debugger : I have some "smart folders" (results of searches) that lead to an uncaught exception "Folder not found".
Probably you should exlude theses smart folder when you build the folders list.
Thank you for your work !

This review is for a previous version of the add-on (1.5.1). 

Hi Enzomas,
I'm really sorry that ThirdStats is not working on your end. This is a known issue (https://github.com/devmount/third-stats/issues/19) and unfortunately not solvable by me, as this is an issue in the Thunderbird core. It has been fixed already, but will only be available with the next major release of Thunderbird (v91). I'm afraid you'll have to wait until then.