exchange.delska.com has no NS records.
NS records for this zone are defined at delska.com.
NS records for this zone are defined at delska.com.
Question and response
Question
dig exchange.delska.com. NS
Answer
The response has no answer records.
Authority
delska.com. 1800 SOA nola.ns.cloudflare.com. dns.cloudflare.com. 2397788830 10000 2400 604800 1800
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0