mmmail02.activetrail.com has no NS records.
NS records for this zone are defined at activetrail.com.
NS records for this zone are defined at activetrail.com.
Question and response
Question
dig mmmail02.activetrail.com. NS
Answer
The response has no answer records.
Authority
activetrail.com. 3600 SOA dns1.p07.nsone.net. hostmaster.nsone.net. 1628672097 3600 600 604800 3600
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0