mx.prime-loc.com has no CNAME records.
Question and response
Question
dig mx.prime-loc.com. NS
Answer
The response has no answer records.
Authority
prime-loc.com. 3465 SOA dns.prime-loc.com. hostmaster.prime-loc.com. 1862057473 43200 3600 604800 3600
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0