ns2.naamserver.net has no MX records.
Question and response
Question
dig ns2.naamserver.net. MX
Answer
The response has no answer records.
Authority
naamserver.net. 86400 SOA ns.naamserver.net. hostmaster.naamserver.net. 2021102103 14400 3600 604800 86400
Additional
. 0 OPT ; payload 1680, xrcode 0, version 0, flags 0