DKIM, which stands for DomainKeys Identified Mail, is an email authentication system, which hinders email addresses from being forged and email content from being manipulated. This is done by attaching an electronic signature to every email message sent from an address under a certain domain. The signature is generated based on a private key that’s available on the outgoing SMTP mail server and it can be verified with 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 mail service providers. This approach will strengthen your web security markedly and you will know for sure that any e-mail message sent from a business partner, a bank, and so on, is genuine. When you send email messages, the receiver will also be sure that you are indeed the one who has sent them. Any email that appears to be forged may either be flagged as such or may never enter the recipient’s inbox, depending on how the particular provider has chosen to treat such email messages.