spf.mailserver.it has no NS records.
NS records for this zone are defined at mailserver.it.
NS records for this zone are defined at mailserver.it.
Question and response
Question
dig spf.mailserver.it. NS
Answer
The response has no answer records.
Authority
mailserver.it. 86400 SOA ns.kpnqwest.it. hostmaster.ns.kpnqwest.it. 2021100100 86400 7200 604800 86400
Additional
. 0 OPT ; payload 4096, xrcode 0, version 0, flags 0