mxd04.zinca.com has no CNAME records.
Question and response
Question
dig mxd04.zinca.com. NS
Answer
The response has no answer records.
Authority
zinca.com. 1800 SOA edward.ns.cloudflare.com. dns.cloudflare.com. 2395297874 10000 2400 604800 1800
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0