DKIM, which is an acronym for DomainKeys Identified Mail, is an email authentication system, which impedes email headers from being forged and email content from being tampered with. This is done by adding a digital signature to each message sent from an email address under a certain domain name. The signature is published based on a private encryption key that is available on the outgoing email server and it can be verified with a public key, which is available in the global DNS database. Thus, any message with altered content or a forged sender can be spotted by email service providers. This method will enhance your online security substantially and you will know for sure that any message sent from a business associate, a banking institution, and so on, is legitimate. When you send out emails, the recipient will also be sure that you are indeed the one who has sent them. Any email that turns out to be fraudulent may either be marked as such or may never reach the recipient’s inbox, based on how the given provider has chosen to cope with such emails.