o3.mail4.shared.hubspot.com has no NS records.
NS records for this zone are defined at hubspot.com.
NS records for this zone are defined at hubspot.com.
Question and response
Question
dig o3.mail4.shared.hubspot.com. NS
Answer
The response has no answer records.
Authority
hubspot.com. 1800 SOA jerry.ns.cloudflare.com. dns.cloudflare.com. 2399444230 10000 2400 604800 1800
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0