hs2._domainkey.xlhost.com has no NS records.
NS records for this zone are defined at xlhost.com.
NS records for this zone are defined at xlhost.com.
Question and response
Question
dig xlhost-com.hs01b.dkim.hubspotemail.net. NS
Answer
The response has no answer records.
Authority
hs01b.dkim.hubspotemail.net. 180 SOA ns10.digicertdns.com. dns.digicertdns.com. 2048610816 43200 3600 1209600 180
Additional
. 0 OPT ; payload 1280, xrcode 0, version 0, flags 0