DMARC checker
Enter a domain to read its DMARC record: the policy receivers apply to mail that fails, where reports go, and how strict alignment is. Each problem comes with the record that fixes it.
How to read the result
Policy is what receivers do with mail that fails: none delivers it and reports, quarantine sends it to spam, reject refuses it. The usual path is none for a few weeks while you read the reports, then quarantine, then reject.
Aggregate reports (rua) are how you find a service that sends as you without being in SPF or DKIM, before a stricter policy starts blocking it. A record without rua works but leaves you blind.
DMARC passes only when SPF or DKIM passes and matches the From domain, so check SPF too with the SPF checker, or everything at once with the domain health check.
Questions
- Is p=none enough?
- It is enough to meet Gmail and Yahoo's requirement for bulk senders, and it is the right place to start, because the reports show who sends as your domain. It does not stop spoofed mail: that takes p=quarantine or p=reject.
- Where does the DMARC record go?
- In a TXT record at _dmarc.yourdomain.com. A subdomain without its own record falls back to the one on the main domain, where sp= sets the policy for subdomains.
- What do rua and ruf mean?
- rua is where receivers send daily aggregate reports: which servers sent as your domain and whether they passed. ruf is for per-message failure reports, which few receivers send. Set rua at least.
- What is DMARC alignment?
- DMARC passes when SPF or DKIM passes for a domain that matches the From address. Relaxed alignment (the default) accepts any subdomain of the same domain; strict (adkim=s, aspf=s) needs the exact domain, which breaks mail from a sending subdomain.
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