ns3.as9143.net has no MX records.
Question and response
Question
dig ns3.as9143.net. MX
Answer
The response has no answer records.
Authority
as9143.net. 900 SOA ns1.as9143.net. dnsadmin.as9143.net. 110 10800 3600 2419200 900
Additional
. 0 OPT ; payload 1400, xrcode 0, version 0, flags 0