mx10.hkbn.net has no MX records.
Question and response
Question
dig mx10.hkbn.net. MX
Answer
The response has no answer records.
Authority
hkbn.net. 3600 SOA ns1.hkbn.net. sysadm.ns1.hkbn.net. 2026020602 1800 900 604800 3600
Additional
. 0 OPT ; payload 4096, xrcode 0, version 0, flags 0