DomainKeys Identified Mail, or DKIM, is a system for confirming the genuineness of an email message by using an e-signature. When DomainKeys Identified Mail is activated for a given domain name, a public cryptographic key is published to the global DNS database and a private one is kept on the mail server. When a new message is sent, a signature is issued using the private key and when the message is received, that signature is authenticated by the incoming POP3/IMAP server using the public key. Thus, the receiver can easily discern if the email is genuine or if the sender’s email address has been spoofed. A discrepancy will occur if the content of the email message has been modified on its way as well, so DKIM can also be used to ensure that the sent and the delivered email messages are identical and that nothing has been attached or removed. This authentication system will boost your email security, as you can validate the genuineness of the important email messages that you receive and your partners can do the exact same thing with the email messages that you send them. Based on the particular mail service provider’s policies, an email that fails the check may be deleted or may emerge in the recipient’s inbox with a warning notification.