Build a DMARC record — policy, reporting addresses and alignment — with plain-English guidance.
policy
How to use this tool
Monitor first — collect reports before blocking anything.
rua gives you aggregate reports showing who sends as your domain.
Move to quarantine, then reject, lowering pct only if you need a staged rollout.
Add the record as a TXT record at _dmarc.yourdomain.com.
Formula & worked example
v=DMARC1; p=none; rua=mailto:dmarc@example.com; monitors all mail and reports it, without blocking anything yet.
Limitations — read this before you rely on it
This tool builds the record text only — it cannot publish DNS, read your reports, or check SPF/DKIM alignment from a browser. DMARC alone does not authenticate mail; SPF and DKIM must also pass and align.
Frequently asked questions
So you can see in reports whether legitimate senders align before you start quarantining or rejecting mail.
rua is daily aggregate reports (who sent, pass/fail); ruf is per-message forensic reports, which many receivers no longer send.
No — DMARC requires at least one of SPF or DKIM to pass and align with your domain.
As a TXT record at _dmarc.yourdomain.com.
No — DNS publishing and lookup are out of scope for a browser tool. Publish at your DNS host and verify with a DMARC checker.