What is DMARC?
Also called: Domain-based Message Authentication, Reporting and Conformance, DMARC record
DMARC is a DNS TXT record that tells receiving servers what to do with mail claiming to be from your domain that fails authentication. Its policy is none, quarantine or reject, and it asks for reports on who is sending as your domain. It also requires the authenticated domain to match the visible From address.
The p= value is the policy: p=none only asks for reports and blocks nothing, p=quarantine asks for failures to go to spam, and p=reject asks for them to be refused.
DMARC introduced alignment, which is what makes SPF and DKIM protect your brand. A message passes DMARC only if SPF or DKIM passes for a domain that matches the From header, closing the gap that let a spammer pass SPF for their own domain while displaying yours.
Since February 2024 Google and Yahoo have required a DMARC record from bulk senders. p=none meets the requirement while you read the reports, but leaving it there permanently means anyone can still spoof you. BIMI requires a policy of quarantine or reject.
Example
_dmarc.example.com TXT "v=DMARC1; p=reject; rua=mailto:[email protected]"Go deeper
Sources
By SimpleVerifier Team · Last reviewed 2026-10-13 · All 50 glossary terms