DKIM, which is an abbreviation for DomainKeys Identified Mail, is an email authentication system, which prevents email headers from being forged and email content from being modified. This is achieved by attaching an electronic signature to every email message sent from an address under a particular domain. The signature is published based on a private key that is available on the outgoing SMTP mail server and it can be verified by using a public key, which is available in the global DNS database. Thus, any message with altered content or a forged sender can be identified by email providers. This approach will enhance your online security substantially and you will know for sure that any e-mail sent from a business collaborator, a bank, and so on, is an authentic one. When you send emails, the recipient 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 tagged as such or may never show up in the receiver’s inbox, depending on how the particular provider has decided to cope with such messages.