spf.safemail.kpn.com has no NS records.
NS records for this zone are defined at safemail.kpn.com.
NS records for this zone are defined at safemail.kpn.com.
Question and response
Question
dig spf.safemail.kpn.com. NS
Answer
The response has no answer records.
Authority
safemail.kpn.com. 3600 SOA ns1.kpn.net. zonemaster.kpn.com. 2026031901 10800 3600 604800 3600
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0