mail.odn.dk has no CNAME records.
Question and response
Question
dig mail.odn.dk. NS
Answer
The response has no answer records.
Authority
odn.dk. 7200 SOA ns1.dns.services. post.dns.services. 2025101413 10800 3600 1814400 7200
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0