mx2.masav.nl has no CNAME records.
Question and response
Question
dig mx2.masav.nl. NS
Answer
The response has no answer records.
Authority
masav.nl. 416 SOA ns.ezisp.eu. support.b2bsecure.eu. 2026022601 10800 3600 1814400 7200
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0