mx.digimobil.es has no CNAME records.
Question and response
Question
dig mx.digimobil.es. NS
Answer
The response has no answer records.
Authority
digimobil.es. 3600 SOA ns.rdsnet.eu. dns-adm.digimobil.es. 2026021902 1200 180 2016000 3600
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0