As of version 2.1, ProtonMail support PGP encrypted emails from Facebook.
Why should I enable PGP encrypted emails from Facebook?
Facebook notifications can actually contain a lot of sensitive private information. For example, they can contain Facebook password reset links, or details such as who has messaged you on Facebook. While it is certainly true that Facebook has this information, when a notification email is sent, anybody who intercepts your email communications can also gain access to this information (for example, your ISP, your workplace network, or a government agency). Turning on PGP encryption for notification emails from Facebook helps to reduce this risk. ProtonMail is the only email service in the world that provides automatic PGP support out of the box.
To start securing the email communications between Facebook and your ProtonMail email address, all you have to do is follow these 5 easy steps.
2) Using a desktop browser, visit your Facebook profile, and under the section About you will see this window:
Add your ProtonMail email address.
3) Open your public key downloaded from your ProtonMail account, in a text editor.
4) After selecting add “PGP Public Key”, copy and paste the public key from the text editor (above) into the Facebook field, and select the check box indicating “Use this public key to encrypt notification emails that Facebook sends you?”.
Isn’t it a security risk to give my public key to Facebook?
Absolutely not. The public key is exactly that, public. You can share it without compromising the security of your ProtonMail account. By sharing it, you enable others like Facebook to send you encrypted messages.
5) Find the confirmation email that was sent to your ProtonMail address by Facebook, and select “Yes, encrypt notification emails sent to me from Facebook.”
And just like that, you have successfully encrypted all of your communications with Facebook. One step closer to regaining your privacy on the internet.