DMARC is a DNS policy that tells receivers how to handle email failing SPF and DKIM alignment monitor (none), spam-folder (quarantine), or block (reject) and where to send reports.

No. p=none only observes. Google and Yahoo's bulk-sender rules expect enforcement quarantine or reject for best deliverability.

Will DMARC break my legitimate mail?

Only if a sender isn't covered by SPF or DKIM. That's what the monitoring phase with rua reports is for find every legitimate sender first.

Free DMARC Checker Validate Your DMARC Record & Policy

DMARC ties SPF and DKIM together and tells receivers what to do with failures. Enter a domain to read its _dmarc record, grade the policy strength, and confirm reporting (rua) is configured so you actually see who's sending as you.

Domain

How this check works

Fetches the TXT record at _dmarc.yourdomain.

Parses p= (policy), rua= (aggregate reports), sp= (subdomain policy), and pct= (rollout percentage).

Grades the setup: p=none monitors only; p=quarantine or p=reject actually protect the domain.

How to fix common problems

Stuck at p=none

p=none is a monitoring phase, not protection. After 2–4 weeks of clean reports, move to quarantine, then reject.

No rua address

Without rua= you get no aggregate reports and are flying blind. Add a reporting mailbox before enforcing.

Forgetting subdomains

Add sp=reject (or explicit subdomain records) so attackers can't pivot to mail.yourdomain.

Example

'v=DMARC1; p=reject; rua=mailto:dmarc@yourdomain.com; sp=reject; pct=100' full enforcement with reporting. The end state every sending domain should reach.

FAQ

What is DMARC?: DMARC is a DNS policy that tells receivers how to handle email failing SPF and DKIM alignment monitor (none), spam-folder (quarantine), or block (reject) and where to send reports.
Is p=none enough?: No. p=none only observes. Google and Yahoo's bulk-sender rules expect enforcement quarantine or reject for best deliverability.
Will DMARC break my legitimate mail?: Only if a sender isn't covered by SPF or DKIM. That's what the monitoring phase with rua reports is for find every legitimate sender first.

Related tools

Related resources

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