extmail.scalabledns.com has no NS records.
NS records for this zone are defined at scalabledns.com.
NS records for this zone are defined at scalabledns.com.
Question and response
Question
dig extmail.scalabledns.com. NS
Answer
The response has no answer records.
Authority
scalabledns.com. 86400 SOA ns1.scalabledns.com. admin.scalabledns.com. 2016081705 86400 7200 3600000 86400
Additional
. 0 OPT ; payload 1680, xrcode 0, version 0, flags 0