DomainKeys Identified Mail, or DKIM, is a method for confirming the genuineness of an email by using a digital signature. When DKIM is activated for a certain domain name, a public key is published to the global DNS system and a private one is stored on the mail server. When a new email is sent, a signature is generated using the private key and when the message is delivered, that signature is checked by the POP3/IMAP mail server using the public key. Thus, the recipient can easily distinguish if the message is genuine or if the sender’s email address has been forged. A mismatch will occur if the content of the email message has been edited in the meantime as well, so DomainKeys Identified Mail can also be used to make sure that the sent and the received messages are identical and that nothing has been attached or removed. This email authentication system will heighten your email security, as you can validate the legitimacy of the important emails that you receive and your colleagues can do the same with the messages that you send them. Depending on the particular email provider’s adopted policy, an email that fails to pass the check may be removed or may appear in the recipient’s mailbox with a warning notification.