mail.mpower.nl has no CNAME records.
Question and response
Question
dig mail.mpower.nl. NS
Answer
The response has no answer records.
Authority
mpower.nl. 65 SOA ns5.mpower.nl. hostmaster.mpower.nl. 2023052301 18000 3600 1209600 3600
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0