DNS is not just about translating the domain name into an IP address. Querying different record types separately avoids confusing web and email issues.
Basic approach
The A record carries an IPv4 address, the AAAA record carries an IPv6 address. CNAME allows one name to be an alias of another name; MX specifies the server name and preference value for email delivery. Just because a domain has an A record does not indicate that the email configuration is correct.
Application steps
- Identify the experiencing service: web, email, or on-premises name resolution.
- Query by explicitly selecting the relevant record type and register the DNS server used.
- Compare the result with the authoritative DNS configuration; Don't just rely on the browser opening.
Practical example
If email delivery fails while the website is running, examine the MX destination and the address records of that destination instead of changing the A record again. A smaller value in the MX preference number means higher preference.
Interpret the result correctly
DNS record does not prove that the service is running; it just tells you how to achieve it. An issue in the CNAME chain can also affect the end target. Test log content, connectivity, and application response as separate phases.
Source and follow-up reading
Protocol or command details: RFC 1035. The steps and example scenario are IPScans editorial narrative.