mail.caretery.com has no NS records.
NS records for this zone are defined at caretery.com.
NS records for this zone are defined at caretery.com.
Question and response
Question
dig mail.caretery.com. NS
Answer
The response has no answer records.
Authority
caretery.com. 1800 SOA bayan.ns.cloudflare.com. dns.cloudflare.com. 2398184676 10000 2400 604800 1800
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0