mail.midphase.com has no NS records.
NS records for this zone are defined at midphase.com.
NS records for this zone are defined at midphase.com.
Question and response
Question
dig mail.midphase.com. NS
Answer
The response has no answer records.
Authority
midphase.com. 3600 SOA dns1.p01.nsone.net. hostmaster.nsone.net. 1731081753 43200 7200 1209600 3600
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0