postfix.altostratus.co has no NS records.
NS records for this zone are defined at altostratus.co.
NS records for this zone are defined at altostratus.co.
Question and response
Question
dig postfix.altostratus.co. NS
Answer
The response has no answer records.
Authority
altostratus.co. 3600 SOA ns1.reflex.co.za. hostmaster.reflex.co.za. 2017111665 3600 600 1209600 3600
Additional
. 0 OPT ; payload 4000, xrcode 0, version 0, flags 0