smtp.st3.qemailserver.com has no NS records.
NS records for this zone are defined at qemailserver.com.
NS records for this zone are defined at qemailserver.com.
Question and response
Question
dig smtp.st3.qemailserver.com. NS
Answer
The response has no answer records.
Authority
qemailserver.com. 600 SOA pdns111.ultradns.com. hostmaster.qualtrics.com. 1772019695 3600 600 1209600 600
Additional
. 0 OPT ; payload 4096, xrcode 0, version 0, flags 0