Tools
DKIM Checker
Understand DKIM selector, signing, and DNS record readiness for common SMB mail platforms.
Run the checker
✓ Selector lookup
✓ Public key presence
✓ Signing guidance
Why this matters
Understand DKIM selector, signing, and DNS record readiness for common SMB mail platforms. 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.
Breach Horizon principle
Start with public evidence, explain the business impact, then recommend the safest next step.
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 dkim 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.
See what attackers see — before they do.
Run the free passive scan, get a prioritized fix plan, and close the gaps yourself or have us do it for you.