mail.nominalia.com has no CNAME records.
Question and response
Question
dig mail.nominalia.com. NS
Answer
The response has no answer records.
Authority
nominalia.com. 300 SOA dns1.nominalia.com. root.dns1.nominalia.com. 2026022401 86400 7200 2592000 300
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0