_spf.freshbooks.com has no NS records.
NS records for this zone are defined at freshbooks.com.
NS records for this zone are defined at freshbooks.com.
Question and response
Question
dig _spf.freshbooks.com. NS
Answer
The response has no answer records.
Authority
freshbooks.com. 60 SOA ns-cloud-c1.googledomains.com. sysadmin.freshbooks.com. 1 21600 3600 259200 60
Additional
. 0 OPT ; payload 512, xrcode 0, version 0, flags 0