spamfilter.internedserviceshelpdesk.nl has no CNAME records.
Question and response
Question
dig spamfilter.internedserviceshelpdesk.nl. NS
Answer
The response has no answer records.
Authority
internedserviceshelpdesk.nl. 1722 SOA ns3.kpn.net. zonemaster.kpn.com. 2026022601 10800 3600 604800 3600
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0