DMARC, which stands for “Domain-based Message Authentication, Reporting & Conformance”, is an email authentication, policy, and reporting protocol. It builds on the widely deployed SPF and DKIM protocols, adding linkage to the author (“From:”) domain name, published policies for recipient handling of authentication failures, and reporting from receivers to senders, to improve and monitor protection of the domain from fraudulent email.
Domain-based Message Authentication, Reporting & Conformance is the latest and greatest advance in email authentication. But, like SPF (Sender Policy Framework) and DKIM (Domain Keys Identified Mail), it’s sometimes misunderstood. That’s why we’re dedicating the last post of our three-part email authentication series to explaining how it works, and why it matters.