sendgrid.careerbuilder.com has no NS records.
NS records for this zone are defined at careerbuilder.com.
NS records for this zone are defined at careerbuilder.com.
Question and response
Question
dig sendgrid.careerbuilder.com. NS
Answer
The response has no answer records.
Authority
careerbuilder.com. 900 SOA misty.cbjobs.net. root.site.careerbuilder.com. 2014090810 1800 900 1209600 900
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0