reply-mx.s7.exacttarget.com has no NS records.
NS records for this zone are defined at s7.exacttarget.com.
NS records for this zone are defined at s7.exacttarget.com.
Question and response
Question
dig reply-mx.s7.exacttarget.com. NS
Answer
The response has no answer records.
Authority
s7.exacttarget.com. 300 SOA dns1.p01.nsone.net. hostmaster.nsone.net. 1680014287 7200 3600 1209600 3600
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0