DomainKeys Identified Mail, or DKIM, is a method for validating the genuineness of an email message by using an e-signature. When DKIM is activated for a given domain, a public cryptographic 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 issued using the private key and when the message is delivered, the signature is ‘scanned’ by the POP3/IMAP server using the public key. In this way, the receiver can easily tell if the email message is genuine or if the sender’s email address has been forged. A discrepancy will appear if the content of the email has been altered in the meantime as well, so DKIM can also be used to ensure that the sent and the delivered messages are identical and that nothing has been added or removed. This email validation system will boost your email security, since you can verify the legitimacy of the important emails that you get and your partners can do the same with the messages that you send them. Depending on the particular email service provider’s policy, an email that fails the examination may be removed or may appear in the recipient’s mailbox with a warning sign.
