The MTA-STS policy file could not be fetched.

MTASTS_POLICY_UNAVAILABLE · Severity: Error

• ErrorMTASTS_POLICY_UNAVAILABLE

  The MTA-STS policy file could not be fetched.

  Senders fetch the policy from https://mta-sts.<domain>/.well-known/mta-sts.txt with a valid certificate, without following redirects, and accept only status 200 with text/plain. When that fails they apply no policy. The evidence names the reason.

  Recommendation: Serve the policy file over HTTPS with a certificate valid for the mta-sts host name, directly at that path, as text/plain.

Reported by

• Domain health check
• MTA-STS and TLS-RPT check

Available through the API

• Domain health check API
• MTA-STS and TLS-RPT check API

Related findings

• Error MTASTS_INVALID_POLICY The MTA-STS policy file is not valid.
• Error MTASTS_INVALID_RECORD The MTA-STS record has invalid syntax.
• Warning MTASTS_LOW_MAX_AGE The MTA-STS policy has a max_age below one day.
• Info MTASTS_MODE_NONE The MTA-STS policy is in mode none.
• Warning MTASTS_MODE_TESTING The MTA-STS policy is in testing mode.
• Error MTASTS_MULTIPLE_RECORDS More than one MTA-STS record is published.

All findings