mail.kolbsystems.net has no NS records.
NS records for this zone are defined at kolbsystems.net.
NS records for this zone are defined at kolbsystems.net.
Question and response
Question
dig mail.kolbsystems.net. NS
Answer
The response has no answer records.
Authority
kolbsystems.net. 1800 SOA dean.ns.cloudflare.com. dns.cloudflare.com. 2398575379 10000 2400 604800 1800
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0