Glossary

DMARC — What It Is and How to Implement It

DMARC is the policy layer on top of SPF and DKIM. It answers: “If auth fails, junk it? bounce it? just watch?” It also sets where to email XML reports about who sent as your domain.

DMARC Policies

• p=none: watch and report — don’t block yet
• p=quarantine: failed mail should land in spam
• p=reject: failed mail shouldn’t arrive at all

DMARC Alignment

SPF or DKIM has to pass and match the From: domain. ESPs often break that until you add their CNAMEs.

DMARC Reports

Big inboxes ship daily XML zips to your rua= address — who sent, from which IP, pass/fail.

How to Check Your DMARC

Read the TXT on _dmarc in Preflight, or paste aggregate XML into our DMARC tool.