mail.mond.net has no CNAME records.
Question and response
Question
dig mail.mond.net. NS
Answer
The response has no answer records.
Authority
mond.net. 60 SOA dns14.ovh.net. tech.ovh.net. 2026022303 86400 3600 3600000 60
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0