mx01.ibbsonline.com has no CNAME records.
Question and response
Question
dig mx01.ibbsonline.com. NS
Answer
The response has no answer records.
Authority
ibbsonline.com. 6300 SOA ns01.momentumtelecom.com. systems.momentumtelecom.com. 2026022300 10800 3600 604800 38400
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0