mail.hostiserver.com has no NS records.
NS records for this zone are defined at hostiserver.com.
NS records for this zone are defined at hostiserver.com.
Question and response
Question
dig mail.hostiserver.com. NS
Answer
The response has no answer records.
Authority
hostiserver.com. 1800 SOA kinsley.ns.cloudflare.com. dns.cloudflare.com. 2394687358 10000 2400 604800 1800
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0