DKIM (Domain Keys Identified Mail) is a method to authenticate the email sender. It is basically equal to digitally signing your email messages when you send them. The recipient can verify DKIM signatures to find out whether the sender is genuine and it is not a spoofed email message. DKIM information is hidden in the headers of an email message is not visible through the message itself.
If you are using Mozilla Thunderbird as your email client then you can use DKIM Verifier add-on for checking the DKIM signatures of email messages that you receive. It can scan for DKIM signatures inside an email message header, verify its authenticity and tell you whether it was verified or not.
After you install DKIM Verifier in your Thunderbird email client, it will start scanning any message that you view for DKIM signatures. At the very top of the message, you can see DKIM status for that email message. By default, it displays DKIM status only of DKIM information is included in the email message. If there is no DKIM information, it does not display anything.
But we can make changes to the DKIM Verifier settings and make it display DKIM status for all the email messages whether they include DKIM or not. We can also make it visually appealing by enabling a color code for DKIM. If DKIM is fully verified, then it changes sender email background color to green, if it is partially verified the background color is orange, if DKIM is not verified the background color is red and so on.
DKIM Verifier add-on makes it very easy to identify spoofed or scam emails as they do not contain valid DKIM information or do not contain any DKIM information. For example, if receive a message from PayPal asking for documents for verification, first check the email message’s DKIM. You will be surprised to see how many email messages are scam just by using this one add-on.
You can get the DKIM Verifier add-on for Mozilla Thunderbird from https://addons.thunderbird.net/en-US/thunderbird/addon/dkim-verifier/.