Proton Mail Bridge

NOTE: This is a wrapper of the official package, but it is not verified,
affiliated with, or supported by Proton AG.

You need to have a keychain in order to run the Proton Mail Bridge. To allow
access to the keychain, you have to manually connect the password-manager-service plug. See more information about this interface
here: https://snapcraft.io/docs/password-manager-service-interface.

sudo snap connect protonmail-bridge:password-manager-service

Proton Mail Bridge is a desktop application that runs in the background,
encrypting and decrypting messages as they enter and leave your computer.