smtp2.123ce.net has no CNAME records.
Question and response
Question
dig smtp2.123ce.net. NS
Answer
The response has no answer records.
Authority
123ce.net. 133 SOA dns19.ovh.net. tech.ovh.net. 2026020700 43200 3600 2419200 86400
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0