mail.ipowerdns.com has no NS records.
NS records for this zone are defined at ipowerdns.com.
NS records for this zone are defined at ipowerdns.com.
Question and response
Question
dig mail.ipowerdns.com. NS
Answer
The response has no answer records.
Authority
ipowerdns.com. 3600 SOA ns1.ipowerweb.net. hostmaster.ipowerweb.net. 2002101100 80000 3600 604800 86400
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0