the release of the Thunderbird 78.2.1 mail client, in which the built-in OpenPGP support is activated by default for all users, which is used for end-to-end encryption of correspondence and digital signature certification of letters. The new release also disables the use of the MD5, SM2, and SM3 algorithms in the OpenPGP implementation.
The main difference between the built-in OpenPGP support and the previously proposed Enigmail add-on is the use of the library , which provides OpenPGP functionality instead of invoking the external GnuPG utility, as well as using its own keystore, which is not compatible with the GnuPG key file format and uses a master password for protection, the same as that used to protect accounts and S / MIME keys.
Source: opennet.ru