spf.swretail.nl has no NS records.
NS records for this zone are defined at swretail.nl.
NS records for this zone are defined at swretail.nl.
Question and response
Question
dig spf.swretail.nl. NS
Answer
The response has no answer records.
Authority
swretail.nl. 300 SOA ns-cloud-e1.googledomains.com. cloud-dns-hostmaster.google.com. 1 21600 3600 259200 300
Additional
. 0 OPT ; payload 512, xrcode 0, version 0, flags 0