ns.cpinternet.com has no MX records.
Question and response
Question
dig ns.cpinternet.com. MX
Answer
The response has no answer records.
Authority
cpinternet.com. 86400 SOA ns1.ccidns.net. hostmaster.ccidns.net. 1 7200 900 1209600 86400
Additional
. 0 OPT ; payload 4096, xrcode 0, version 0, flags 0