02 / Security & email
Know what the checks can tell you.
A check is a view of specific signals. Understand what was tested, what the result says and what still needs investigation.
Start with the certificate
SSL Checker reports on the certificate and TLS connection presented by a domain. Read the certificate details, expiry and reported issues together. An unsuccessful connection can also reflect reachability at the time of the check.
- Confirm that you checked the hostname you actually use.
- Read the issue description and recommendation before making a change.
- A valid certificate does not establish that the website’s content or application is safe.
Separate the email signals
Email Security and Email Health help inspect a domain’s email configuration. These signals answer different questions; a positive result for one does not replace the others.
- SPF authorizes sending hosts for an SMTP sender domain.
- DKIM uses a signature associated with a signing domain.
- DMARC checks alignment with the visible From domain and publishes the domain owner’s handling preference for failed validation.
Follow the result to the next check
Use Email Header Analyzer when you need to inspect the path and authentication results recorded in a particular message. Check the report’s scope and findings rather than treating a grade as a complete security assessment.
- Domain checks describe the configuration they can observe.
- Header analysis describes the headers supplied for that message; it does not prove that every header is trustworthy.
- Fix a specific finding with the responsible service provider, then run the relevant check again.
Who owns the domain? Read our WHOIS guide.