mx01.agentspam.com has no CNAME records.
Question and response
Question
dig mx01.agentspam.com. NS
Answer
The response has no answer records.
Authority
agentspam.com. 3563 SOA NS.CYBERLYNK.NET. DNSADMIN.CYBERLYNK.NET. 2024062901 10800 3600 604800 3600
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0