64.71.78.154.hosted.at.cloudsouth.com has no MX records.
Question and response
Question
dig 64.71.78.154.hosted.at.cloudsouth.com. MX
Answer
The response has no answer records.
Authority
hosted.at.cloudsouth.com. 3600 SOA ns.cloudsouth.net. hostmaster.cloudsouth.com. 1771953393 10800 3600 604800 3600
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0