spf1.sage.com has no NS records.
NS records for this zone are defined at sage.com.
NS records for this zone are defined at sage.com.
Question and response
Question
dig spf1.sage.com. NS
Answer
The response has no answer records.
Authority
sage.com. 1800 SOA rita.ns.cloudflare.com. dns.cloudflare.com. 2397700678 10000 2400 604800 1800
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0