mail.mcb.dk has no CNAME records.
Question and response
Question
dig mail.mcb.dk. NS
Answer
The response has no answer records.
Authority
mcb.dk. 243 SOA ns.mcb.dk. hostmaster.mcb.dk. 2026030101 10800 3600 2592000 38400
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0