mail.panorama.com.mx has no CNAME records.
Question and response
Question
dig mail.panorama.com.mx. NS
Answer
The response has no answer records.
Authority
panorama.com.mx. 577 SOA ns.panorama.com.mx. eleon.panorama.com.mx. 2025103101 10800 3600 1209600 10800
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0