_spf.ipoac.nl has no CNAME records.
Question and response
Question
dig _spf.ipoac.nl. NS
Answer
The response has no answer records.
Authority
ipoac.nl. 3600 SOA ns1.ipoac.nl. hostmaster.ipoac.nl. 2026030569 14400 3600 3600000 3600
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0