DMARC — glossary
TL;DR
Domain-based Message Authentication — policy telling receivers how to handle SPF/DKIM failures.
Key facts
- Term
- DMARC
TL;DR
DMARC tells receiving mail servers what to do when SPF or DKIM fail — none, quarantine, or reject — and where to send aggregate reports.
Minimum viable record
v=DMARC1; p=none; rua=mailto:dmarc@yourdomain.com
Start with p=none to collect reports without blocking legitimate mail, then tighten policy once SPF and DKIM are solid.
Why resellers care
One compromised WordPress contact form can poison the IP reputation for every account on the server. DMARC plus monitoring catches authentication drift before customers open spam-folder tickets.