Install claws-mail-pgpmime by entering the following commands in the terminal:
sudo apt update sudo apt install claws-mail-pgpmime
Description:
PGP/MIME plugin for Claws Mail
This plugin for Claws Mail verifies signatures and decrypts messages. It does also provide the PGP/core plugin for use with other privacy plugins, required also for signing and encrypting mails.
Homepage: http://www.claws-mail.org
Version: 3.16.0-1
Section: universe/mail