Rated 5 out of 5 stars

le Roger V. ar Meith. 20, 2021 · buan-nasc

Extremely useful tool for filing emails in Thunderbird (and it does several other things besides, but that's mainly what I use it for.)
Re the latest update being broken by changes in Thunderbird (2.3.1 with Thunderbird 78.11.0) the "disable-enable" trick as described by Opto has saved me from going crazy the other day, so thanks! :-)
Edit: latest version is 2.38, and the "disable-enable" trick is no longer needed, for my environment at least (Win 10 on a fairly fast Lenovo P310 Xeon E3-1240v5 workstation)
It still has a few bugs, but I'm giving the developer 5/5 for his dedication to the job. :-)