What is DMARC?

DMARC, or Domain-based Message Authentication, Reporting & Conformance, is an email authentication protocol that builds upon existing SPF (Sender Policy Framework) and DKIM (DomainKeys Identified Mail) protocols designed to give domain owners the ability to protect their domain from unauthorized use, such as email spoofing.

By implementing DMARC, domain owners can specify how email receivers should handle messages that fail authentication checks and receive reports on email activity related to their domain. By implementing DMARC, organizations can significantly reduce the risk of domain spoofing and phishing, protect their brand reputation, and improve email deliverability.

How it works?

DMARC works by leveraging two existing email authentication protocols, SPF (Sender Policy Framework) and DKIM (DomainKeys Identified Mail). The receiving server will check if either SPF or DKIM PASSED for the email, then it will check if the Return-Path domain used by SPF and/or the d= domain used by DKIM aligns with From: domain,

Finally, it will extract the DMARC policy published by the domain found in the “From” address and comply with the policy.

The overall logic is:

If SPF PASSED and ALIGNED with the “From” domain = DMARC PASS, or
If DKIM PASSED and ALIGNED with the “From” domain = DMARC PASS
If both SPF and DKIM FAILED = DMARC FAIL

DMARC not only requires that SPF or DKIM PASS, but it also requires the domains used by either one of those two protocols to ALIGN with the domain found in the “From” address. Only then will DMARC PASS.

Which part of the email does the DMARC protocol focus on?

DMARC focuses on the domain found in the From: or Header from header which is visible to the end user and indicates the sender's domain. DMARC ensures this domain matches those used in SPF and DKIM checks, providing a way to authenticate the email's source and prevent spoofing.

Begin your DMARC journey and learn more about DMARC and our Managed DMARC Compliance Services or contact us today 1.888.982.7940.