Domain-based Message Authentication Reporting and Conformance (DMARC) is a free and open technical specification that is used to authenticate an email by aligning SPF and DKIM mechanisms. By having DMARC in place, domain owners large and small can fight business email compromise, phishing and spoofing. Co-authored by dmarcian’s founder, DMARC was first published in 2012.
With DMARC you can tell the world how to handle the unauthorized use of your email domains by instituting a policy in your DMARC record. The three DMARC policies are: