maile.osgbilling.com has no NS records.
NS records for this zone are defined at osgbilling.com.
NS records for this zone are defined at osgbilling.com.
Question and response
Question
dig maile.osgbilling.com. NS
Answer
The response has no answer records.
Authority
osgbilling.com. 180 SOA ns10.digicertdns.com. dns.digicertdns.com. 2009011100 43200 3600 1209600 180
Additional
. 0 OPT ; payload 1280, xrcode 0, version 0, flags 0