DKIM, which is an abbreviation for DomainKeys Identified Mail, is an email validation system, which prevents email headers from being spoofed and email content from being manipulated. This is done by adding a digital signature to each and every email sent from an address under a given domain name. The signature is issued based on a private encryption key that is available on the SMTP email server and it can be validated with a public key, which is available in the global Domain Name System. In this way, any email message with altered content or a forged sender can be identified by mail service providers. This method will boost your online security considerably and you will know for sure that any e-mail message sent from a business collaborator, a bank, etc., is a genuine one. When you send out messages, the recipient will also be sure that you are indeed the one who has sent them. Any email message that turns out to be forged may either be labeled as such or may never reach the receiver’s mailbox, depending on how the given provider has chosen to treat such email messages.