smtp.hicoria.com has no NS records.
NS records for this zone are defined at hicoria.com.
NS records for this zone are defined at hicoria.com.
Question and response
Question
dig smtp.hicoria.com. NS
Answer
The response has no answer records.
Authority
hicoria.com. 1800 SOA lily.ns.cloudflare.com. dns.cloudflare.com. 2395415735 10000 2400 604800 1800
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0