correoweb.c6p.net has no CNAME records.
Question and response
Question
dig correoweb.c6p.net. NS
Answer
The response has no answer records.
Authority
c6p.net. 1800 SOA aragorn.ns.cloudflare.com. dns.cloudflare.com. 2398371593 10000 2400 604800 1800
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0