dns3.netvpn.net has no MX records.
Question and response
Question
dig dns3.netvpn.net. MX
Answer
The response has no answer records.
Authority
netvpn.net. 300 SOA ns1.acvan.net. postmaster.netvpn.net. 2026021008 21600 3600 1209600 300
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0