DomainKeys Identified Mail, or DKIM, is a method for checking the legitimacy of an email using an electronic signature. When DomainKeys Identified Mail is enabled for a particular domain, a public cryptographic key is published to the global DNS database and a private one is kept on the mail server. If a new email message is sent, a signature is generated using the private key and when the email message is received, the signature is ‘scanned’ by the POP3/IMAP mail server using the public key. In this way, the recipient can easily distinguish if the message is authentic or if the sender’s address has been spoofed. A mismatch will occur if the content of the email has been modified in the meantime as well, so DKIM can also be used to ensure that the sent and the delivered emails are identical and that nothing has been attached or removed. This email authentication system will enhance your email security, as you can verify the genuineness of the important email messages that you receive and your partners can do the exact same thing with the emails that you send them. Depending on the particular mail service provider’s adopted policy, an email that fails to pass the check may be deleted or may emerge in the recipient’s mailbox with a warning notification.