xensub.net has no MX records.
Question and response
Question
dig xensub.net. MX
Answer
The response has no answer records.
Authority
xensub.net. 1800 SOA christina.ns.cloudflare.com. dns.cloudflare.com. 2397561367 10000 2400 604800 1800
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0