DKIM, which is an abbreviation for DomainKeys Identified Mail, is an authentication system, which blocks email headers from being forged and email content from being manipulated. This is done by attaching a digital signature to every email sent from an address under a certain domain name. The signature is issued based on a private encryption key that is available on the outbound email server and it can be validated by using a public key, which is available in the global Domain Name System. Thus, any email with altered content or a spoofed sender can be spotted by email providers. This approach will strengthen your web security dramatically and you will be sure that any e-mail message sent from a business associate, a banking institution, etc., is a legitimate one. When you send messages, the recipient will also know for sure that you are indeed the one who has sent them. Any mail that turns out to be phony may either be marked as such or may never appear in the receiver’s mailbox, depending on how the particular provider has chosen to deal with such messages.