Gpgtools GPG Keychain Access

https://emailselfdefense.fsf.org/en/ promotes GnuPG Ed bot to test the OpenPGP mail setup.

Unsure how to best approach this. Either have an GPG Keychain option / Test mail Wizard guiding through this test or we could also add the public key of Ed bot to GPG Keychain by default, although that then won't teach users that they need the public key of the recipient first and how to look for that. The FSFs approach isn't really safe against outside attacks. Instead of giving the full fingerprint, they just give one digit of the Key ID "C" - that's it. Steve would not be happy adapting this 1:1.

But the bot works and is a much better idea than manually dealing with all user test mails and also better than sending a test mail to yourself.

Here's what the Tutorial from FSF says:

Step 3.a
Send Edward your public key

This is a special step that you won't have to do when corresponding with real people. In your email program's menu, go to Enigmail → Key Management. You should see your key in the list that pops up. Right click on your key and select Send Public Keys by Email. This will create a new draft message, as if you had just hit the Write button.

Address the message to edward-en@fsf.org. Put at least one word (whatever you want) in the subject and body of the email. Don't send yet.

The lock icon in the top left should be yellow, meaning encryption is turned on. We want this first special message to be unencrypted, so click the icon once to turn it off. The lock should become grey, with a blue dot on it (to alert you that the setting has been changed from the default). Once encryption is off, hit Send.

It may take two or three minutes for Edward to respond. In the meantime, you might want to skip ahead and check out the Use it Well section of this guide. Once he's responded, head to the next step. From here on, you'll be doing just the same thing as when corresponding with a real person.

When you open Edward's reply, GnuPG may prompt you for your password before using your private key to decrypt it.

Step 3.b
Send a test encrypted email

Write a new email in your email program, addressed to edward-en@fsf.org. Make the subject "Encryption test" or something similar and write something in the body.

The lock icon in the top left of the window should be yellow, meaning encryption is on. This will be your default from now on.

Next to the lock, you'll notice an icon of a pencil. We'll get to this in a moment.

Click Send. Enigmail will pop up a window that says "Recipients not valid, not trusted or not found."

To encrypt an email to Edward, you need his public key, so now you'll have Enigmail download it from a keyserver. Click Download Missing Keys and use the default in the pop-up that asks you to choose a keyserver. Once it finds keys, check the first one (Key ID starting with C), then select ok. Select ok in the next pop-up.

Now you are back at the "Recipients not valid, not trusted or not found" screen. Check the box in front of Edward's key and click Send.

Since you encrypted this email with Edward's public key, Edward's private key is required to decrypt it. Edward is the only one with his private key, so no one except him can decrypt it.