DomainKeys Identified Mail, or DKIM, is a system for validating the legitimacy of an email message by using an e-signature. When DKIM is enabled for a given domain, a public encryption key is published to the global DNS system and a private one is kept on the email server. If a new email is sent, a signature is issued using the private key and when the email message is delivered, that signature is validated by the incoming email server using the public key. In this way, the receiver can easily tell if the email message is authentic or if the sender’s email address has been forged. A discrepancy will occur if the content of the email has been changed in the meantime as well, so DKIM can also be used to make sure that the sent and the received emails are identical and that nothing has been added or erased. This validation system will enhance your email security, as you can validate the legitimacy of the important email messages that you receive and your colleagues can do the same with the email messages that you send them. Based on the given email service provider’s policies, an email message that fails the examination may be removed or may emerge in the recipient’s mailbox with a warning notification.
