mx.registrarmail.net has no CNAME records.
Question and response
Question
dig mx.registrarmail.net. NS
Answer
The response has no answer records.
Authority
registrarmail.net. 300 SOA ns1.tucows.com. hostmaster.tucows.com. 2026012101 10800 3600 2592000 300
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0