ns30.nwnnetwork.net has no MX records.
Question and response
Question
dig ns30.nwnnetwork.net. MX
Answer
The response has no answer records.
Authority
nwnnetwork.net. 1800 SOA ns1.nwnnetwork.net. dnsadmin.nwnnetwork.net. 2018011709 10800 1800 604800 1800
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0