mta.operadors.cat has no CNAME records.
Question and response
Question
dig mta.operadors.cat. NS
Answer
The response has no answer records.
Authority
operadors.cat. 10800 SOA ns1.operadors.cat. admin.operadors.cat. 2025073102 10800 3600 648000 38400
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0