x.nic.xyz has no MX records.
Question and response
Question
dig x.nic.xyz. MX
Answer
The response has no answer records.
Authority
nic.xyz. 3600 SOA ns0.centralnic-dns.com. hostmaster.centralnic-dns.com. 1770994970 300 300 604800 3600
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0