DomainKeys Identified Mail, or DKIM, is a method for confirming the genuineness of an email message by using an e-signature. When DKIM is enabled for a given domain name, a public encryption key is published to the global DNS system and a private one is stored on the mail server. If a new email message is sent, a signature is issued using the private key and when the message is received, the signature is authenticated by the incoming POP3/IMAP server using the public key. In this way, the recipient can easily discern if the email message is genuine or if the sender’s email address has been spoofed. A discrepancy will appear if the content of the email message has been changed on its way as well, so DKIM can also be used to ensure that the sent and the delivered email messages are identical and that nothing has been added or deleted. This authentication system will increase your email safety, as you can validate the legitimacy of the important email messages that you receive and your colleagues can do the same with the messages that you send them. Depending on the given email service provider’s policies, a message that fails the test may be erased or may be delivered to the receiver’s mailbox with a warning symbol.
