Network Diagnostics and More
Tool guide limitationsGuides explain the intended workflow but cannot cover every device, provider or operating condition.

Interfaces and external services can change. Follow the current on-screen controls, check dates and vendor documentation, and verify important results independently before acting on them.

Important: Do not rely on this result alone for purchasing, configuration, security, safety, compliance, contractual or fault-diagnosis decisions. Results can be incomplete, delayed, misleading or wrong. Verify important findings with the relevant provider, manufacturer documentation and an appropriate independent test or qualified professional.

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DNS and email

Email Domain Health guide

Run a passive public-DNS and HTTPS-policy audit without an SMTP server.

Open Email Domain Health

What you need

  • Public domain
  • Optional known DKIM selectors

How to use it

  1. 1Enter the domain.
  2. 2Add selectors from each sender platform if known.
  3. 3Run the complete audit.
  4. 4Review evidence, recommendations and record templates.

Understanding the results

  • Review items need investigation; informational results may be optional controls rather than faults.

Recommended next actions

  • Confirm proposed records with the mail provider before publishing.

Common problems

  • Unknown selectors and resolver propagation can leave checks incomplete.

Privacy and security

  • Only public lookup data is requested. Avoid entering internal names, credentials or confidential notes.

Worked example

Scenario
Reviewing a Microsoft 365 domain
Example input
example.com; selector1 and selector2
How to read it
The audit compares SPF, DKIM, DMARC, MX and transport-policy evidence without connecting to a mail server.

Limitations

  • Does not prove live delivery, mailbox acceptance, reputation or negotiated SMTP/TLS sessions.

Do not rely on one result for a production, security, safety, purchasing or contractual decision. Verify important findings independently.