vmail.dial-up.net has no NS records.
NS records for this zone are defined at dial-up.net.
NS records for this zone are defined at dial-up.net.
Question and response
Question
dig vmail.dial-up.net. NS
Answer
The response has no answer records.
Authority
dial-up.net. 600 SOA ns1.is.co.za. support.is.co.za. 2021121001 28800 7200 604800 10800
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0