DomainKeys Identified Mail, or DKIM, is a system for validating the genuineness of an email using a digital signature. When DKIM is activated for a specific domain, a public encryption key is published to the global DNS system and a private one is stored on the email server. If a new email message is sent, a signature is generated using the private key and when the email message is received, that signature is checked by the POP3/IMAP email server using the public key. Thus, the receiver can easily recognize if the message is genuine or if the sender’s email address has been spoofed. A mismatch will appear if the content of the email has been edited on its way as well, so DKIM can also be used to ensure that the sent and the delivered emails are identical and that nothing has been added or erased. This authentication system will strengthen your email safety, as you can verify the authenticity 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 policies, a message that fails to pass the examination may be deleted or may show up in the receiver’s inbox with a warning alert.