mail-a01.ithnet.com has no NS records.
NS records for this zone are defined at ithnet.com.
NS records for this zone are defined at ithnet.com.
Question and response
Question
dig mail-a01.ithnet.com. NS
Answer
The response has no answer records.
Authority
ithnet.com. 3600 SOA ns.ithnet.com. hostmaster.ithnet.com. 2026020402 9000 1800 650000 86400
Additional
. 0 OPT ; payload 4096, xrcode 0, version 0, flags 0