MTA-STS Checker
Check whether a domain publishes MTA-STS and TLS reporting records for safer mail transport.
Why this matters
Check whether a domain publishes MTA-STS and TLS reporting records for safer mail transport. The goal is not to create noise. The goal is to turn a visible security signal into a clear next action a business owner, MSP, or IT lead can understand.
What to check
- Confirm the public signal exists and is current.
- Record the evidence in a way another person can validate.
- Separate urgent exposure from normal hygiene work.
- Link the finding to a remediation guide, tool, or assessment.
Recommended workflow
- Run the check or read the assessment criteria.
- Save the visible evidence.
- Decide whether the finding affects email trust, web trust, identity, backup, or compliance evidence.
- Fix the highest-confidence issue first.
- Re-test and document the new result.
Output to keep
| Evidence | Why it matters | Owner | | --- | --- | --- | | Current public result | Establishes baseline | IT / MSP | | Recommended change | Shows next action | Technical owner | | Retest result | Proves closure | Reviewer |
FAQ
Is the mta-sts checker free?
Yes. Breach Horizon content and public-surface checks are designed as free entry points. Some remediation links may be affiliate links and are disclosed.
Does this require internal access?
No. Tool pages are built around public-surface checks and educational guidance unless clearly stated otherwise.
Find the gaps attackers check first.
Start with a public-surface check, then use the guides and assessments to fix what matters.