Question 670
A company cannot explain why an old DNS mail exchanger still appears in public records. Which evidence most strongly validates the intended interpretation or control?
Explanation
Correct Answer
The observed MX values match the latest authoritative zone response. This answer directly addresses the described constraint. Current DNS answers identify public mail routing independently of internal diagrams. Successful validation requires: The observed MX values match the latest authoritative zone response.
Incorrect Answers
This result applies to a different case: A client asks testers to discover public subdomains without sending packets to the client's servers. Certificate issuance logs expose hostnames passively but do not prove current ownership. It does not establish the present requirement, where the observed MX values match the latest authoritative zone response. The relevant evidence is: The observed MX values match the latest authoritative zone response.
That approach concerns a different situation: a client wants the passive discovery of hosts from public certificate names and DNS records. Multiple passive sources reduce the chance of relying on a stale artifact. The required result is that the observed MX values match the latest authoritative zone response. The relevant evidence is: The observed MX values match the latest authoritative zone response.
That relates to a different issue: An organization wants publicly exposed SSL certificate history for a retired hostname. Certificates can reveal previously registered names and issuance chronology. That is not a direct remedy for the requested outcome: The observed MX values match the latest authoritative zone response. The relevant evidence is: The observed MX values match the latest authoritative zone response.