Import a certificate in Evolution mail client

Solution 1:

This answer was inspired by this one: How do I make a digital certificate available to LibreOffice Writer for digital signatures?

To import a certificate in Evolution (tested on Debian 9):

1. Once you have a certificate, install it on your computer by double-clicking on it.
2. Open Evolution.
3. Open Edit -> Preferences.
4. In the left panel, click Certificates.
5. Import your certificate by clicking import and selecting your certificate.
6. In the top of the current menu, click Authorities.
7. Find the CA that provided your certificate. You can find that. information in the certificate itself by double-clicking on it.
8. Click edit and check the options you desire. If you trust that CA, you can check all three.

If you are still interested in making a free certificate, and for others like myself trying to figure all that certificate thing, the website www.cacert.org allows you to do so.

However, this CA (Certification Authority) is not yet recognized by browsers by default, therefore if you need your certificate to encrypt a website, the client will have to validate it zirself*.

Have a good day.

*Third-person gender less pronoun as suggested on https://en.wikipedia.org/wiki/Third-person_pronoun#Summary.