mc.hostchain.net has no MX records.
Question and response
Question
dig mc.hostchain.net. MX
Answer
The response has no answer records.
Authority
hostchain.net. 86400 SOA ns1.hostchain.net. sysadmin.generalsupport.net. 2026022502 3600 1800 1209600 86400
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0