MTA-STS policy can't be fetched
Check id: mta_sts.policy_unreachable · fix effort: medium
What it means
You advertise a mail encryption policy but the policy file itself won't load. Senders can't apply it.
The technical detail
The _mta-sts TXT exists but the policy at https://mta-sts.<domain>/.well-known/mta-sts.txt failed to fetch or parse. Redirects are not allowed on that path.
How to fix it
- Serve the policy file over valid HTTPS at the well-known path. no redirects allowed.
- Verify content:
version: STSv1,mode:,mx:lines,max_age:.
Does your domain have this problem?
Run a free scan, takes about ten seconds.