DomainKeys Identified Mail, or DKIM, is a system for verifying the genuineness of an email using an e-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 kept on the mail server. When a new email message is sent, a signature is generated using the private key and when the email is received, that signature is authenticated by the incoming email server using the public key. Thus, the receiver can easily distinguish if the email is authentic or if the sender’s email address has been spoofed. A mismatch will occur if the content of the email message has been changed on its way as well, so DKIM can also be used to make sure that the sent and the received emails are identical and that nothing has been added or erased. This validation system will heighten your email safety, as you can verify the legitimacy of the important email messages that you get and your colleagues can do the exact same thing with the emails that you send them. Depending on the particular email service provider’s adopted policy, a message that fails to pass the test may be deleted or may end up in the recipient’s inbox with a warning flag.