DomainKeys Identified Mail, or DKIM, is a method for verifying the legitimacy of an email by using an e-signature. When DomainKeys Identified Mail is enabled for a given domain, a public cryptographic key is published to the global Domain Name System and a private one is stored on the mail server. If a new email is sent, a signature is issued using the private key and when the email is received, the signature is validated by the incoming POP3/IMAP mail server using the public key. In this way, the recipient can easily discern if the email message is authentic or if the sender’s email address has been spoofed. A mismatch will appear if the content of the email has been modified on its way as well, so DKIM can also be used to ensure that the sent and the received emails are identical and that nothing has been attached or removed. This validation system will increase your email safety, as you can validate the authenticity of the important emails that you receive and your partners can do likewise with the messages that you send them. Depending on the given mail service provider’s policies, an email that fails the test may be deleted or may show up in the receiver’s mailbox with a warning alert.
