naamservert.nl has no MX records.
Question and response
Question
dig naamservert.nl. MX
Answer
The response has no answer records.
Authority
naamservert.nl. 86400 SOA ns1.naamservert.nl. hostmaster.naamservert.nl. 2018090607 28800 7200 604800 86400
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0