DomainKeys Identified Mail, or DKIM, is a method for checking the legitimacy of an email using a digital signature. When DKIM is activated for a given domain name, a public encryption key is published to the global Domain Name System and a private one is stored on the mail server. If a new email is sent, a signature is issued using the private key and when the email message is delivered, that signature is authenticated by the POP3/IMAP mail server using the public key. In this way, the receiver can easily know if the message is authentic or if the sender’s address has been spoofed. A discrepancy will appear if the content of the email message has been modified in the meantime as well, so DKIM can also be used to make sure that the sent and the received email messages are identical and that nothing has been added or deleted. This authentication system will increase your email safety, as you can verify the legitimacy of the important email messages that you receive and your partners can do likewise with the messages that you send them. Depending on the given email service provider’s policy, an email message that fails the examination may be erased or may reach the receiver’s inbox with a warning.