mobile.kpn.net has no MX records.
Question and response
Question
dig mobile.kpn.net. MX
Answer
The response has no answer records.
Authority
mobile.kpn.net. 3600 SOA ns7.kpn.net. zonemaster.kpn.com. 2022021601 900 600 604800 3600
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0