demoserver.myorderbox.com has no MX records.
Question and response
Question
dig demoserver.myorderbox.com. MX
Answer
The response has no answer records.
Authority
myorderbox.com. 1800 SOA andy.ns.cloudflare.com. dns.cloudflare.com. 2398548868 10000 2400 604800 1800
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0