smtp.ultipro.com has no NS records.
NS records for this zone are defined at ultipro.com.
NS records for this zone are defined at ultipro.com.
Question and response
Question
dig smtp.ultipro.com. NS
Answer
The response has no answer records.
Authority
ultipro.com. 1800 SOA chloe.ns.cloudflare.com. dns.cloudflare.com. 2397955596 10000 2400 604800 1800
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0