mail.etermin.net has no CNAME records.
Question and response
Question
dig mail.etermin.net. NS
Answer
The response has no answer records.
Authority
etermin.net. 600 SOA ns03.domaincontrol.com. dns.jomax.net. 2025120300 28800 7200 604800 600
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0