emailserver3.serverpoint.com has no CNAME records.
Question and response
Question
dig emailserver3.serverpoint.com. NS
Answer
The response has no answer records.
Authority
serverpoint.com. 202 SOA ns1.serverpoint.com. dns.cloudflare.com. 2396157340 10000 2400 604800 1800
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0