DKIM, which is short for DomainKeys Identified Mail, is a validation system, which prevents email headers from being spoofed and email content from being meddled with. This is done by adding a digital signature to every email message sent from an email address under a specific domain. The signature is generated on the basis of a private cryptographic key that is available on the outgoing SMTP email server and it can be verified using a public key, which is available in the global Domain Name System. Thus, any message with changed content or a forged sender can be recognized by email service providers. This method will increase your online security significantly and you’ll be sure that any e-mail message sent from a business collaborator, a bank, and so on, is a genuine one. When you send out emails, the recipient will also be sure that you are indeed the one who has sent them. Any mail that appears to be fake may either be tagged as such or may never show up in the recipient’s inbox, depending on how the particular provider has decided to deal with such email messages.