mx.designry.net has no NS records.
NS records for this zone are defined at designry.net.
NS records for this zone are defined at designry.net.
Question and response
Question
dig mx.designry.net. NS
Answer
The response has no answer records.
Authority
designry.net. 3600 SOA dns.designry.net. hostmaster.designry.net. 1323840664 43200 3600 604800 3600
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0