spf-01.bizmail.nifty.com has no NS records.
NS records for this zone are defined at bizmail.nifty.com.
NS records for this zone are defined at bizmail.nifty.com.
Question and response
Question
dig spf-01.bizmail.nifty.com. NS
Answer
The response has no answer records.
Authority
bizmail.nifty.com. 900 SOA odns0.nifty.ad.jp. hostmaster.nifty.ad.jp. 202602260 3600 900 604800 900
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0