Is Your MTA-STS Policy Actually Protecting Mail?
Type a domain — the checker reads its live _mta-sts TXT record over DNS, fetches the published MTA-STS policy file, and checks the policy's mx patterns against your real MX hosts. Runs entirely in your browser. No signup.
MTA-STS only protects inbound mail when the TXT record, the policy file, and the mx coverage all line up. No record at all? Build one first.
Check your MTA-STS record
Enter a domain below. The checker reads the live TXT record at _mta-sts + your domain over encrypted DNS, fetches the published policy file, and checks whether the policy's mx patterns cover your real MX hosts.
Record broken or missing? Have a specialist double-check it — the $49 Email Domain Trust Audit is a fixed-output report with risk notes and prioritized next steps.
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