DKIM, which is an abbreviation for DomainKeys Identified Mail, is an email authentication system, which stops email addresses from being spoofed and email content from being tampered with. This is achieved by attaching a digital signature to each message sent from an address under a certain domain name. The signature is generated on the basis of a private key that is available on the SMTP server and it can be validated by using a public key, which is available in the global DNS database. Thus, any email with altered content or a forged sender can be recognized by email providers. This method will heighten your online security substantially and you’ll be sure that any message sent from a business partner, a banking institution, and so on, is genuine. When you send out emails, the receiver will also know for sure that you are indeed the one who has sent them. Any email that appears to be bogus may either be labeled as such or may never appear in the recipient’s mailbox, depending on how the given provider has decided to treat such messages.