DomainKeys Identified Mail, or DKIM, is a system for verifying the legitimacy of an email using an e-signature. When DKIM is enabled for a given domain name, a public cryptographic key is published to the global Domain Name System and a private one is stored on the mail server. When a new message is sent, a signature is issued using the private key and when the email message is delivered, that signature is validated by the POP3/IMAP email server using the public key. Thus, the recipient can easily know if the message is authentic or if the sender’s email address has been spoofed. A mismatch will appear if the content of the email message has been modified on its way as well, so DomainKeys Identified Mail can also be used to ensure that the sent and the received messages are identical and that nothing has been added or deleted. This authentication system will boost your email security, as you can validate the genuineness of the important emails that you get and your associates can do the exact same thing with the messages that you send them. Depending on the particular mail service provider’s adopted policy, a message that fails the check may be removed or may show up in the receiver’s inbox with a warning symbol.