mail01.oracle.netsuite.com has no NS records.
NS records for this zone are defined at netsuite.com.
NS records for this zone are defined at netsuite.com.
Question and response
Question
dig mail01.oracle.netsuite.com. NS
Answer
The response has no answer records.
Authority
netsuite.com. 600 SOA a1-124.akam.net. dnsadmin.nsgbu.internal. 2603011445 10800 3600 604800 3600
Additional
. 0 OPT ; payload 4096, xrcode 0, version 0, flags 0