mx2.dada.eu has no CNAME records.
Question and response
Question
dig mx2.dada.eu. NS
Answer
The response has no answer records.
Authority
dada.eu. 543 SOA ns1.register.it. hostmaster.register.it. 2024060404 10800 3600 604800 86400
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0