mx-01.bzctoons.net has no CNAME records.
Question and response
Question
dig mx-01.bzctoons.net. NS
Answer
The response has no answer records.
Authority
bzctoons.net. 213 SOA ns1.bzctoons.net. bzctoons.gmail.com. 2026020100 3600 600 1209600 3600
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0