spf1.spf.atom.com has no NS records.
NS records for this zone are defined at atom.com.
NS records for this zone are defined at atom.com.
Question and response
Question
dig spf1.spf.atom.com. NS
Answer
The response has no answer records.
Authority
atom.com. 1800 SOA frank.ns.cloudflare.com. dns.cloudflare.com. 2397474527 10000 2400 604800 1800
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0