ns3.distance.net has no MX records.
Question and response
Question
dig ns3.distance.net. MX
Answer
The response has no answer records.
Authority
distance.net. 3600 SOA ns2.distance.net. dns.distance.net. 2021061500 3600 600 1209600 3600
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0