DKIM, which stands for DomainKeys Identified Mail, is an email authentication system, which stops email headers from being forged and email content from being meddled with. This is achieved by adding an electronic signature to each message sent from an email address under a certain domain name. The signature is issued on the basis of a private cryptographic key that is available on the SMTP mail server and it can be validated with a public key, which is available in the global Domain Name System. Thus, any message with altered content or a forged sender can be identified by mail service providers. This approach will heighten your online safety considerably and you will be sure that any email sent from a business ally, a bank, etc., is a genuine one. When you send email messages, the receiver will also be sure that you are indeed the one who has sent them. Any mail that appears to be forged may either be marked as such or may never appear in the receiver’s mailbox, depending on how the given provider has chosen to treat such email messages.