mail.tanhost.com has no NS records.
NS records for this zone are defined at tanhost.com.
NS records for this zone are defined at tanhost.com.
Question and response
Question
dig mail.tanhost.com. NS
Answer
The response has no answer records.
Authority
tanhost.com. 1440 SOA ns1.tanhost.com. admin.support.tanhost.com. 2025111804 86400 7200 3600000 1440
Additional
. 0 OPT ; payload 1680, xrcode 0, version 0, flags 0