mx.lb.network.bit.nl has no CNAME records.
Question and response
Question
dig mx.lb.network.bit.nl. NS
Answer
The response has no answer records.
Authority
network.bit.nl. 555 SOA nsauth1.bit.nl. hostmaster.bit.nl. 2025121201 28800 7200 604800 600
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0