mx.onetwistedpair.com has no CNAME records.
Question and response
Question
dig mx.onetwistedpair.com. NS
Answer
The response has no answer records.
Authority
onetwistedpair.com. 555 SOA ns77.domaincontrol.com. dns.jomax.net. 2026021117 28800 7200 604800 600
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0