3945285.spf06.hubspotemail.net has no NS records.
NS records for this zone are defined at spf06.hubspotemail.net.
NS records for this zone are defined at spf06.hubspotemail.net.
Question and response
Question
dig 3945285.spf06.hubspotemail.net. NS
Answer
The response has no answer records.
Authority
spf06.hubspotemail.net. 180 SOA ns10.digicertdns.com. dns.digicertdns.com. 2009010104 43200 3600 1209600 180
Additional
. 0 OPT ; payload 1280, xrcode 0, version 0, flags 0