DMARC Builder & Validator

Build a new DMARC record from scratch, or paste one to check it against RFC 7489 syntax.

Policy (p=)

NoneMonitoring only. Nothing is blocked.QuarantineFailing mail is sent to spam.RejectFailing mail is refused outright.

Reporting

Aggregate reports (rua) — one email per line

Also collect forensic reports (ruf)Most organizations don't need this — aggregate reports (rua) are usually sufficient.

Advanced (optional)

Subdomain policy (sp)

"Inherit" omits sp= — per RFC 7489 that means subdomains already follow p=, not that they're unprotected. Set it explicitly if you want subdomain policy to stay fixed even if p= changes later.

Non-existent subdomains (np)

Defaulted to reject: a subdomain that doesn't exist should never send mail, and not every receiver yet supports the implicit fallback for np=.

DKIM alignment (adkim)

SPF alignment (aspf)

Mark as testing (t=y)Replaces the deprecated pct= rollout tag — signals receivers that the domain is still being validated, without applying policy to only a percentage of mail.

Generated DMARC record

v=DMARC1; p=none; np=reject; adkim=r; aspf=r

Publish this as a TXT record at _dmarc.yourdomain.com. Generated entirely in your browser — nothing is sent anywhere.

What this tool does

The builder assembles a valid DMARC TXT record from a form, and the validator checks the syntax of a record you already have — both run entirely in your browser, so nothing you type is sent to a server or logged.

Build a record — choose a policy (none, quarantine or reject), add aggregate (rua=) and optionally forensic (ruf=) reporting addresses, and set subdomain policy, alignment mode, and other advanced tags without memorizing RFC 7489 syntax.
Validate a record — paste in an existing record and get a tag-by-tag breakdown plus any syntax errors, without needing to look the record up from DNS first.

Once published, use the DMARC Analyzer to confirm the live record resolves correctly over DNS. To build the underlying SPF record too, use the SPF Builder.

Frequently asked questions

Is the DMARC builder free?

Yes. Building or validating a DMARC record is free and doesn't require an account or email address.

Does the builder publish the record for me?

No. The record is generated entirely in your browser — nothing is sent to a server. You publish it yourself as a TXT record at _dmarc.yourdomain.com through your DNS provider.

What's the difference between the builder and the analyzer?

The builder creates a new record from scratch or validates syntax you paste in, without touching DNS. The DMARC Analyzer instead looks up a real domain's currently published record over live DNS and reports on its actual enforcement status.