mail1234.corp.generalmills.com has no NS records.
NS records for this zone are defined at generalmills.com.
NS records for this zone are defined at generalmills.com.
Question and response
Question
dig mail1234.corp.generalmills.com. NS
Answer
The response has no answer records.
Authority
generalmills.com. 900 SOA mgoextdns1.genmills.com. dom\.admin.genmills.com. 15899 900 600 2419200 900
Additional
. 0 OPT ; payload 1220, xrcode 0, version 0, flags 0