What is DMARC?
DMARC (Domain-based Message Authentication, Reporting & Conformance) is an email authentication protocol that builds on SPF and DKIM. It helps domain owners protect their email from phishing.
A DMARC policy tells receiving mail servers what to do when an email fails authentication: reject it, quarantine it, or take no action.
DMARC Policy Levels
p=none
Monitoring only. No enforcement on failed emails.
p=quarantine
Suspicious emails go to spam/junk folder.
p=reject
Unauthorized emails are completely blocked.