Review for Sieve by Firefox user 313fed
Rated 5 out of 5 stars
https://github.com/thsmi/sieve/
Several years ago Mozilla made a strange decision. They dropped their very flexible addon system and copied the extremely limited WebExtensions from Google Chrome. An this ultimately meant for Thunderbird that "classic" addons will go way.
Now in 2020 classic Thunderbird addons are dead. Which meant for the addon it needed to evolve and drop its Thunderbird dependencies. It is now a portable standalone application!
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