mh-core.metrohive.net has no MX records.
Question and response
Question
dig mh-core.metrohive.net. MX
Answer
The response has no answer records.
Authority
metrohive.net. 86400 SOA pcelica.neobee.net. dns.neobee.net. 2016072901 28800 14400 3600000 86400
Additional
. 0 OPT ; payload 4096, xrcode 0, version 0, flags 0