postoffice.omnis.com has no NS records.
NS records for this zone are defined at omnis.com.
NS records for this zone are defined at omnis.com.
Question and response
Question
dig postoffice.omnis.com. NS
Answer
The response has no answer records.
Authority
omnis.com. 900 SOA primary.guardeddns.net. dns-admin.guardeddns.net. 3670 28800 450 1209600 900
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0