DomainKeys Identified Mail, or DKIM, is a method for verifying the legitimacy of an email message by using an e-signature. When DKIM is activated for a given domain, a public encryption key is published to the global DNS system and a private one is kept on the email server. When a new message is sent, a signature is generated using the private key and when the message is received, the signature is checked by the POP3/IMAP server using the public key. Thus, the recipient can easily discern if the email message is genuine or if the sender’s address has been spoofed. A mismatch will occur if the content of the email message has been edited on its way as well, so DKIM can also be used to make sure that the sent and the delivered messages are identical and that nothing has been attached or erased. This email validation system will strengthen your email security, as you can confirm the legitimacy of the important emails that you receive and your colleagues can do likewise with the emails that you send them. Depending on the given email service provider’s adopted policy, an email message that fails to pass the check may be removed or may end up in the recipient’s inbox with a warning symbol.