A message will fail DMARC if the message fails both (1) SPF or SPF alignment and (2) DKIM or DKIM alignment. DMARC allows senders to instruct email providers on how to handle unauthenticated mail via a DMARC policy, removing any guesswork on how they should handle messages that fail DMARC authentication.

How do I fix DMARC failure?

To resolve this issue, you should immediately opt for full DMARC compliance at your organization by aligning and authenticating all outgoing messages against both SPF and DKIM, as for an email to pass DMARC authentication, the email would be required to pass either SPF or DKIM authentication and alignment.

What is DMARC and how does it work?

Domain-based Message Authentication, Reporting, and Conformance, or DMARC, is a technical standard that helps protect email senders and recipients from spam, spoofing, and phishing. … Specifically, DMARC establishes a method for a domain owner to: Publish its email authentication practices.