mx.fundaments.nl has no NS records.
NS records for this zone are defined at fundaments.nl.
NS records for this zone are defined at fundaments.nl.
Question and response
Question
dig mx.fundaments.nl. NS
Answer
The response has no answer records.
Authority
fundaments.nl. 1800 SOA clay.ns.cloudflare.com. dns.cloudflare.com. 2397054147 10000 2400 604800 1800
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0