DKIM, which is an acronym for DomainKeys Identified Mail, is an authentication system, which hinders email addresses from being forged and email content from being tampered with. This is done by adding an electronic signature to each and every message sent from an address under a given domain. The signature is generated based on a private encryption key that is available on the outgoing SMTP mail server and it can be verified using a public key, which is available in the global Domain Name System. Thus, any message with modified content or a spoofed sender can be spotted by mail service providers. This approach will boost your worldwide web security substantially and you will know for sure that any email message sent from a business ally, a banking institution, etc., is a legitimate one. 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 forged may either be marked as such or may never show up in the receiver’s mailbox, depending on how the particular provider has decided to handle such messages.