Defaults.Exposed › September 2026 census › v10 registry › DMARC policy
DMARC policy
Methodology v10 · canonical ID dmarc-policy · Email Security · scored · census as of September 5, 2026
The instruction that tells mail providers to reject impersonated email, the core anti-spoofing control.
Definition
| Canonical ID | dmarc-policy |
|---|---|
| Category | Email Security |
| Grade impact | Scored, counts toward the grade |
| Pass | A valid DMARC record at _dmarc.<domain> with an enforcing policy (p=quarantine or p=reject). |
| Fail | No DMARC record, an unparseable record, or a monitor-only policy (p=none) which observes but does not block. |
| Example (passing) | v=DMARC1; p=reject; rua=mailto:[email protected] |
No-data rule: when this check couldn't be determined for a domain (timeout, SERVFAIL, redacted source) it returns N/A and is excluded from that domain's scoring denominator: "couldn't determine" is never counted as a failure. "Determined absent" is a real fail.
Prevalence across the census
11.6% of graded domains publish an enforcing DMARC policy (p=quarantine or p=reject) (36,598,025 of 316,600,902, as of September 5, 2026).
A further share publish a monitor-only p=none record; that counts as a DMARC record but not enforcement.
Census denominator: 316,600,902 graded domains. Aggregates only: never an individual domain's result.
Fix it
Plain-English impact, cost of ignoring it, and step-by-step remediation: defaults.exposed/fix/dmarc
Cite this check
Defaults.Exposed, "DMARC policy (dmarc-policy)", Grading Methodology v10 (census as of September 5, 2026). https://defaults.exposed/v10/methodology/dmarc-policy
Permalink: https://defaults.exposed/v10/methodology/dmarc-policy ·
All 34 checks: v10 registry ·
Machine-readable: /v10/methodology/checks.json ·
Licence: open data