Purpose
DMARC connects the visible author domain with SPF or DKIM through alignment. The _dmarc TXT record requests handling of validation failures. A successful DNS check is not a message authentication result.
Policies
none is monitoring; quarantine and reject request stricter handling. rua requests aggregate reports. Introduce stricter settings after checking legitimate sending services.
Parent domains
Current DMARC uses bounded DNS tree walks for discovery. sp and np describe different subdomain cases. Older implementations can differ. Our check shows the discovered record; it does not verify DKIM signatures, external reporting authorization or inbox delivery.
Interpreting a yellow result
A monitoring policy can be intentional. The yellow signal asks you to read the explanation, not to change p to reject immediately. If our result identifies a parent domain, consider where you intend to publish the policy. Changing a parent record can affect more than the name you entered. Keep the old record available when planning changes.