DomainKeys Identified Mail, or DKIM, is a method for validating the authenticity of an email using a digital signature. When DomainKeys Identified Mail is activated for a given domain name, a public cryptographic key is published to the global DNS database and a private one is kept on the mail server. When a new message is sent, a signature is issued using the private key and when the email is received, that signature is checked by the incoming POP3/IMAP email server using the public key. In this way, the receiver can easily discern if the email message is legitimate or if the sender’s email address has been spoofed. A mismatch will occur if the content of the email message has been changed on its way as well, so DomainKeys Identified Mail can also be used to ensure that the sent and the delivered emails are identical and that nothing has been added or deleted. This authentication 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 exact same thing with the messages that you send them. Depending on the particular mail service provider’s adopted policy, a message that fails to pass the examination may be erased or may emerge in the recipient’s mailbox with a warning alert.
