DomainKeys Identified Mail, or DKIM, is a system for checking the genuineness of an email by using an e-signature. When DomainKeys Identified Mail is enabled for a given domain name, a public 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 received, the signature is validated by the POP3/IMAP email server using the public key. In this way, the recipient can easily know if the message is legitimate or if the sender’s address has been spoofed. A mismatch will occur if the content of the email has been altered in the meantime 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 erased. This authentication system will increase your email safety, since you can validate the genuineness of the important email messages that you get and your colleagues can do the exact same thing with the email messages that you send them. Depending on the particular mail service provider’s policies, a message that fails the examination may be deleted or may reach the receiver’s inbox with a warning sign.
