DKIM, which is an acronym for DomainKeys Identified Mail, is an authentication system, which stops email addresses from being forged and email content from being modified. This is done by attaching an e-signature to each and every email message sent from an email address under a given domain. The signature is issued on the basis of a private cryptographic key that’s available on the SMTP mail server and it can be verified using a public key, which is available in the global Domain Name System. Thus, any email with modified content or a spoofed sender can be spotted by email service providers. This method will increase your web security enormously and you’ll be sure that any message sent from a business associate, a banking institution, etc., is legitimate. When you send out emails, the recipient will also know for sure that you are indeed the one who has sent them. Any mail that turns out to be bogus may either be tagged as such or may never show up in the receiver’s mailbox, based on how the particular provider has chosen to cope with such emails.