Rated 5 out of 5 stars

This is a great add-on that will definitely help you be more efficient in managing your inbox. The reason I'm writing this review is because I realized how much I relied on it now that it's not available anymore for the latest version of Thunderbird. Hoping we'll get an update soon! Thank you for this great add-on.

This review is for a previous version of the add-on (4.18.1). 

Thanks for your encouraging words - there already is a functional prerelease here:
make sure you follow the instructions there exactly so you can install it.