spf.nucleus.be has no NS records.
NS records for this zone are defined at nucleus.be.
NS records for this zone are defined at nucleus.be.
Question and response
Question
dig spf.nucleus.be. NS
Answer
The response has no answer records.
Authority
nucleus.be. 86400 SOA ns3.combell.net. dnsmaster.nucleus.be. 1769157088 3600 1800 2419200 86400
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0