spf.mailpam.com has no NS records.
NS records for this zone are defined at mailpam.com.
NS records for this zone are defined at mailpam.com.
Question and response
Question
dig spf.mailpam.com. NS
Answer
The response has no answer records.
Authority
mailpam.com. 3600 SOA ns1.dnsimple.com. admin.dnsimple.com. 1503537966 86400 7200 604800 300
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0