spf.unione.io has no NS records.
NS records for this zone are defined at unione.io.
NS records for this zone are defined at unione.io.
Question and response
Question
dig spf.unione.io. NS
Answer
The response has no answer records.
Authority
unione.io. 180 SOA ns10.dnsmadeeasy.com. dns.dnsmadeeasy.com. 2009011834 43200 3600 1209600 180
Additional
. 0 OPT ; payload 1280, xrcode 0, version 0, flags 0