DomainKeys Identified Mail, or DKIM, is a method for validating the authenticity of an email message by using an electronic signature. When DKIM is enabled for a specific domain, a public encryption key is published to the global DNS system and a private one is stored on the mail server. If a new message is sent, a signature is issued using the private key and when the email is delivered, that signature is ‘scanned’ by the incoming mail server using the public key. In this way, the recipient can easily discern if the email message is legitimate or if the sender’s email address has been spoofed. A mismatch will appear if the content of the email has been altered in the meantime as well, so DomainKeys Identified Mail can also be used to make sure that the sent and the received messages are identical and that nothing has been attached or removed. This validation system will strengthen your email security, since you can confirm the authenticity of the important emails that you receive and your partners can do likewise with the emails that you send them. Based on the particular email provider’s policy, an email message that fails to pass the check may be removed or may reach the receiver’s inbox with a warning symbol.
