DMARC
DMARC (Domain-based Message Authentication, Reporting and Conformance) is a DNS TXT record that builds on SPF and DKIM by telling receiving mail servers what policy to apply when a message fails both checks -- p=none (monitor only), p=quarantine (send to spam), or p=reject (refuse outright) -- and where to send aggregate reports (rua) summarizing authentication results across all senders using the domain. DMARC also requires "alignment": the domain in SPF or DKIM must match the domain the recipient sees in the From header, closing a gap where a message could pass SPF or DKIM for an unrelated domain. DMARC is defined in RFC 7489.
By AdminKit team, Netbase JSC · Updated