mx2.controldeservidor.com has no CNAME records.
Question and response
Question
dig mx2.controldeservidor.com. NS
Answer
The response has no answer records.
Authority
controldeservidor.com. 3600 SOA ns1.controldeservidor.com. servidores.loading.es. 2025112501 10800 3600 604800 10800
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0