MTASTS-POLICY-UNREACHABLE
MTA-STS policy file cannot be fetched
What it means
The DNS record advertises a policy, but senders cannot download it, so they cannot apply it. In enforce mode some senders may refuse to deliver.
How to fix it
- 1Serve https://mta-sts.yourdomain/.well-known/mta-sts.txt with a valid certificate for mta-sts.yourdomain.
Re-check after the change
DNS changes can take up to the record's TTL to be seen; use Re-run on the result page to bypass our 10-minute cache.