opssmtp.idibill.com has no NS records.
NS records for this zone are defined at idibill.com.
NS records for this zone are defined at idibill.com.
Question and response
Question
dig opssmtp.idibill.com. NS
Answer
The response has no answer records.
Authority
idibill.com. 86400 SOA edns1.ultradns.com. premiumdns.support.neustar. 2019073367 28800 7200 1209600 86400
Additional
. 0 OPT ; payload 4096, xrcode 0, version 0, flags 0