Install Thunderbird
sudo apt-get install thunderbird
Install gnupg
sudo apt update
sudo apt-get install gnupg
Install enigmail (Thunderbird gpg extension)
sudo apt-get install enigmail
Generate keys with gpg
See gpg
Select keys in Thunderbird
Open Thunderbird and apply keys:
- Navigate to Account Settings > [select account] > OpenPGP Security
- Select Enable OpenPGP support for this identity
- Select Use specific OpenPGP key ID and then Select Key