mail.licence.lu has no CNAME records.
Question and response
Question
dig mail.licence.lu. NS
Answer
The response has no answer records.
Authority
licence.lu. 10800 SOA ns1.eurodns.com. hostmaster.eurodns.com. 2023042600 86400 7200 604800 86400
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0