# What is DMARC?

> DMARC is an email-authentication, policy, and reporting protocol that lets a domain owner publish a requested handling policy for messages that fail DMARC validation and specify where receivers should send reports.

- Canonical URL: https://yellowcube.eu/glossary/domain-based-message-authentication-reporting-and-conformance/
- Publisher: Yellow Cube
- Language: en
- Contact: hello@yellowcube.eu

## Content

A message passes DMARC when at least one supported authentication method — SPF or DKIM — passes and its authenticated domain aligns with the domain visible in the From address.

The domain owner publishes a DNS record containing a requested policy such as `p=none`, `p=quarantine`, or `p=reject`. Reports help identify legitimate senders, configuration errors, and unauthorized use. Deployment normally begins with monitoring and moves toward enforcement after valid mail streams are authenticated and aligned.

### Key points

- **SPF contribution:** SPF authenticates the MAIL FROM domain against an authorized sending system; DMARC then checks its alignment with the visible From domain.
- **DKIM contribution:** DKIM validates a cryptographic signature and its signing domain; DMARC then checks that domain’s alignment with the visible From domain.
- **Policy role:** Tells receivers the domain owner’s requested treatment for mail that fails; final handling remains with the receiver.
- **Important limitation:** DMARC does not encrypt mail, judge message content, authenticate a human author, or stop abuse of lookalike domains and compromised legitimate accounts.

### Related terms

[Sender Policy Framework (SPF)](<https://yellowcube.eu/glossary/sender-policy-framework/>) · [DomainKeys Identified Mail (DKIM)](<https://yellowcube.eu/glossary/domainkeys-identified-mail/>) · [Email spoofing](<https://yellowcube.eu/glossary/email-spoofing/>) · [Email security](<https://yellowcube.eu/glossary/email-security/>) · [Business email compromise (BEC)](<https://yellowcube.eu/glossary/business-email-compromise/>)

### Sources

[RFC 9989: Domain-Based Message Authentication, Reporting, and Conformance](https://www.rfc-editor.org/info/rfc9989/) · [NIST SP 800-177r1: Trustworthy Email](https://csrc.nist.gov/pubs/sp/800/177/r1/final)

## Attribution and scope

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