[lucastx]

For a much more gentle (and illustrated) introduction do public-key encryption, GnuPG and how to use it with email (Thunderbird + Enigmail), see FSF's Email Self-Defense:

https://emailselfdefense.fsf.org/

Tactical Tech's Security in-a-Box has more detailed, step-by-step, multiple platform guides for the same tools:

https://securityinabox.org/en/guide/thunderbird/windows

https://securityinabox.org/en/guide/thunderbird/linux

https://securityinabox.org/en/guide/thunderbird/os-x

[Esau]

Thank you.