mx.speakeasy.net has no NS records.
NS records for this zone are defined at speakeasy.net.
NS records for this zone are defined at speakeasy.net.
Question and response
Question
dig mx.speakeasy.net. NS
Answer
The response has no answer records.
Authority
speakeasy.net. 300 SOA ns1.megapath.net. support.megapath.net. 1761226104 14400 3600 2718281828 300
Additional
. 0 OPT ; payload 4096, xrcode 0, version 0, flags 0