mx.bookmarkz.net has no NS records.
NS records for this zone are defined at bookmarkz.net.
NS records for this zone are defined at bookmarkz.net.
Question and response
Question
dig mx.bookmarkz.net. NS
Answer
The response has no answer records.
Authority
bookmarkz.net. 3600 SOA dns.bookmarkz.net. hostmaster.bookmarkz.net. 1241434253 43200 3600 604800 3600
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0