mail.itns.email.mx has no CNAME records.
Question and response
Question
dig mail.itns.email.mx. NS
Answer
The response has no answer records.
Authority
email.mx. 1086 SOA ns2.tecnocity.net. sinter.gapsnet.com. 2026010701 3600 1800 1209600 86400
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0