mail.atginternet.com has no NS records.
NS records for this zone are defined at atginternet.com.
NS records for this zone are defined at atginternet.com.
Question and response
Question
dig mail.atginternet.com. NS
Answer
The response has no answer records.
Authority
atginternet.com. 86400 SOA ns1.atginternet.com. hosting.atginternet.com. 2026022600 3600 1800 1209600 86400
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0