DomainKeys Identified Mail, or DKIM, is a method for verifying the legitimacy of an email message using an electronic signature. When DKIM is enabled for a certain domain, a public encryption key is published to the global DNS system and a private one is stored on the email server. If a new email message is sent, a signature is generated using the private key and when the email is received, that signature is authenticated by the incoming email server using the public key. In this way, the recipient can easily distinguish if the email is genuine or if the sender’s address has been spoofed. A mismatch will appear if the content of the email message has been changed in the meantime as well, so DKIM can also be used to ensure that the sent and the delivered emails are identical and that nothing has been added or deleted. This email authentication system will strengthen your email security, since you can confirm the legitimacy of the important emails that you get and your partners can do the same with the emails that you send them. Based on the given email service provider’s policy, a message that fails to pass the test may be deleted or may end up in the recipient’s mailbox with a warning sign.