spf.renater.fr has no NS records.
NS records for this zone are defined at renater.fr.
NS records for this zone are defined at renater.fr.
Question and response
Question
dig spf.renater.fr. NS
Answer
The response has no answer records.
Authority
renater.fr. 300 SOA ns1.renater.fr. hostmaster.renater.fr. 2016440604 21600 3600 3600000 172800
Additional
. 0 OPT ; payload 4096, xrcode 0, version 0, flags 0