DomainKeys Identified Mail, or DKIM, is a method for confirming the legitimacy of an email using an electronic signature. When DomainKeys Identified Mail is enabled for a specific domain name, a public key is published to the global DNS system and a private one is kept on the mail server. If a new email is sent, a signature is issued using the private key and when the email is received, that signature is ‘scanned’ by the incoming mail server using the public key. Thus, the receiver can easily distinguish if the email is legitimate or if the sender’s email address has been forged. A mismatch will appear if the content of the email message has been changed on its way as well, so DKIM can also be used to make sure that the sent and the received email messages are identical and that nothing has been attached or erased. This email authentication system will boost your email safety, as you can verify the legitimacy of the important emails that you get and your colleagues can do the exact same thing with the emails that you send them. Based on the given email provider’s adopted policy, a message that fails the test may be erased or may appear in the recipient’s mailbox with a warning symbol.