mx3.bitnl.eu has no CNAME records.
Question and response
Question
dig mx3.bitnl.eu. NS
Answer
The response has no answer records.
Authority
bitnl.eu. 14 SOA get.desec.io. get.desec.io. 2025105632 86400 3600 2419200 3600
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0