mx.channelguide.net has no NS records.
NS records for this zone are defined at channelguide.net.
NS records for this zone are defined at channelguide.net.
Question and response
Question
dig mx.channelguide.net. NS
Answer
The response has no answer records.
Authority
channelguide.net. 3600 SOA dns.channelguide.net. hostmaster.channelguide.net. 1415667713 43200 3600 604800 3600
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0