smtp4.cdk.com has no NS records.
NS records for this zone are defined at cdk.com.
NS records for this zone are defined at cdk.com.
Question and response
Question
dig smtp4.cdk.com. NS
Answer
The response has no answer records.
Authority
cdk.com. 300 SOA ns.las.us.cdk.com. domain-admin.cobaltgroup.com. 2026021701 3600 900 1209600 300
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0