DomainKeys Identified Mail, or DKIM, is a system for validating the genuineness of an email message by using an electronic signature. When DKIM 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. If a new email is sent, a signature is issued using the private key and when the message is delivered, the signature is authenticated by the incoming email server using the public key. Thus, the recipient can easily distinguish if the email message is genuine or if the sender’s address has been spoofed. A discrepancy will occur if the content of the email message has been modified in the meantime as well, so DomainKeys Identified Mail can also be used to make sure that the sent and the received email messages are identical and that nothing has been added or removed. This authentication system will enhance your email security, since you can confirm the genuineness of the important emails that you get and your partners can do the same with the email messages that you send them. Based on the given email provider’s policies, an email that fails the test may be erased or may appear in the receiver’s inbox with a warning.