DMARC (Domain-based Message Authentication)

What is DMARC (Domain-based Message Authentication)?

DMARC builds on SPF and DKIM by adding a policy layer. Domain owners publish a DMARC record in DNS specifying what to do with emails that fail authentication: none (monitor only), quarantine (send to spam), or reject (block entirely). DMARC also enables reporting — receiving servers send aggregate reports about authentication results back to the domain owner, providing visibility into who is sending email on their behalf. Proper DMARC implementation is essential for preventing email spoofing and brand impersonation.