gruponp.entregaemail.com has no CNAME records.
Question and response
Question
dig gruponp.entregaemail.com. NS
Answer
The response has no answer records.
Authority
entregaemail.com. 1800 SOA kim.ns.cloudflare.com. dns.cloudflare.com. 2398370792 10000 2400 604800 1800
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0