mx1.izzi.mx has no CNAME records.
Question and response
Question
dig mx1.izzi.mx. NS
Answer
The response has no answer records.
Authority
izzi.mx. 300 SOA a1-229.akam.net. fmmartineza.izzi.mx. 2024100264 900 1800 2592000 86400
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0