DomainKeys Identified Mail, or DKIM, is a system for verifying the legitimacy of an email 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 email server. When a new email is sent, a signature is generated using the private key and when the email message is delivered, that signature is checked by the POP3/IMAP server using the public key. Thus, the receiver can easily tell if the email message is legitimate or if the sender’s email address has been forged. A discrepancy will appear if the content of the email message has been modified on its way as well, so DomainKeys Identified Mail can also be used to make sure that the sent and the delivered email messages are identical and that nothing has been added or deleted. This validation system will boost your email safety, since you can validate the legitimacy 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. Based on the particular mail service provider’s adopted policy, an email message that fails to pass the test may be removed or may emerge in the receiver’s inbox with a warning flag.