OpenPGP support in Thunderbird 78 (summer 2020 release) Integrated support for OpenPGP messaging https://wiki.mozilla.org/Thunderbird:OpenPGP:2020 Blog entry: Thunderbird, Enigmail and OpenPGP (October 8, 2019)
Enigmail users: do not update to Thunderbird 78 July 1, 2020 https://posteo.de/en/blog/enigmail-users-do-not-update-to-thunderbird-78