ns3.ns71.net has no MX records.
Question and response
Question
dig ns3.ns71.net. MX
Answer
The response has no answer records.
Authority
ns71.net. 1800 SOA gail.ns.cloudflare.com. dns.cloudflare.com. 2397275619 10000 2400 604800 1800
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0