xyz has no MX records.
Question and response
Question
dig xyz. MX
Answer
The response has no answer records.
Authority
xyz. 900 SOA ns0.centralnic.net. hostmaster.centralnic.net. 3000839097 900 1800 6048000 3600
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0