DomainKeys Identified Mail, or DKIM, is a method for checking the genuineness of an email message using an e-signature. When DKIM is activated 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 email server. If a new message is sent, a signature is generated using the private key and when the email is received, the signature is verified by the incoming mail server using the public key. In this way, the receiver can easily distinguish if the email is genuine or if the sender’s address has been spoofed. A discrepancy will occur if the content of the email has been modified on its way as well, so DomainKeys Identified Mail 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 boost your email security, since you can verify the authenticity of the important emails that you receive and your colleagues can do likewise with the email messages that you send them. Based on the particular email provider’s policies, an email that fails the test may be removed or may appear in the recipient’s mailbox with a warning sign.