DomainKeys Identified Mail, or DKIM, is a system for confirming the legitimacy of an email message by using a digital signature. When DKIM is activated for a specific domain, a public encryption key is published to the global DNS database and a private one is stored on the email server. If a new message is sent, a signature is generated using the private key and when the email message is delivered, that signature is checked by the incoming POP3/IMAP email server using the public key. Thus, the receiver can easily tell if the email is authentic or if the sender’s email address has been forged. A discrepancy will occur if the content of the email message has been altered on its way as well, so DomainKeys Identified Mail can also be used to make sure that the sent and the delivered emails are identical and that nothing has been attached or removed. 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 same with the email messages that you send them. Based on the particular email provider’s policy, an email that fails to pass the test may be erased or may reach the receiver’s mailbox with a warning alert.