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Security

SPF/DMARC Checker

An SPF and DMARC checker reads a domain published email authentication records and reports what they permit. SPF lists which servers may send for the domain; DMARC tells receivers what to do when a message fails. Together they decide whether your mail is delivered, quarantined, or silently spoofable.

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What do SPF and DMARC records control?

SPF publishes which systems may send mail for a domain, while DMARC tells receivers how to handle messages that fail aligned SPF or DKIM checks and where to send reports. Reading both records helps diagnose delivery failures, spoofing exposure, policy rollout, and the services authorized to represent a domain.

The checker resolves TXT records at the domain root and at _dmarc through the server's DNS resolver. It cannot discover a DKIM record without a selector and does not send a test message. SPF's ten-DNS-lookup limit and nested includes require review beyond simply finding a v=spf1 string.