DMARC Record Signal Test
The DMARC Record Test fetches the DMARC policy published in your domain's _dmarc TXT record and validates the policy, alignment mode, percentage, and reporting addresses. DMARC ties together SPF and DKIM, telling receiving mail servers what to do when authentication fails (none / quarantine / reject) and where to send aggregate reports about who is sending mail as your domain. Without DMARC, you have no visibility into who is spoofing your brand and no way to tell receivers to reject those forgeries.
What This Tool Checks
- _dmarc TXT record exists
- Policy mode (none, quarantine, reject)
- Alignment mode (relaxed vs strict)
- Percentage of mail subject to policy (pct=)
- Aggregate report address (rua=)
- Forensic report address (ruf=)
- Subdomain policy (sp=)
Why It Matters for SEO
DMARC is the only mechanism that gives receivers a clear policy for failed-authentication mail. p=none gives you visibility but no enforcement; p=quarantine sends failures to spam; p=reject blocks them entirely. Without a DMARC policy, your domain is freely spoofable even if you have SPF and DKIM. With p=reject, attackers cannot send mail as you to any receiver that honours DMARC (which is now most major providers).
How to Fix It
Publish a DMARC TXT record at _dmarc.yourdomain.com starting with p=none plus an rua= report address. Use the aggregate reports to verify all legitimate senders pass authentication. After 4-8 weeks, move to p=quarantine, then p=reject. Set sp=reject for subdomains.
How It Works
We query the _dmarc TXT record at your domain, parse its policy directives, and validate the syntax against RFC 7489. The aggregate / forensic report addresses are checked for validity. The current policy strength (none / quarantine / reject) is reported with the recommended next step.
Common Mistakes to Avoid
- No DMARC record at all (no policy, no visibility)
- p=none in production for years without ever moving to enforcement
- No aggregate report address (rua=) so you have no visibility
- p=reject deployed before SPF / DKIM are correctly configured (legitimate mail bounces)
- Missing subdomain policy (sp=) leaving subdomains unprotected
Quick Checklist
- DMARC record published at _dmarc.yourdomain.com
- Aggregate reports collected via rua=
- Policy progressed from none to quarantine to reject
- Subdomain policy (sp=) explicitly set
- Re-tested after each policy change