mx2.comendosystems.net has no MX records.
Question and response
Question
dig mx2.comendosystems.net. MX
Answer
The response has no answer records.
Authority
mx2.comendosystems.net. 3600 SOA ns1.electric.net. dns.electric.net. 1453845396 10000 1800 604800 3600
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0