DMARC: Domain-based Message Authentication, Reporting and Conformance
DMARC is a DNS policy that tells receivers what to do with mail that fails SPF and DKIM checks tied to the visible "From" domain, and where to send reports.
How it works
The policy is "none" (only report), "quarantine" (treat as suspicious) or "reject" (refuse). The record sits at the _dmarc name of the domain and can ask receivers for summary reports.
A domain with a strict DMARC policy is harder to impersonate. A missing policy is common on old or small domains and is a mild signal on its own.
Related LookValid products
| Product | Credits | Docs |
|---|---|---|
| Email Domain Check | 1 credit per address checked | API docs |
New to the API? Start with the quickstart or the API reference. Agents can call the same lookups through the MCP server.