mail.t2systems.com has no NS records.
NS records for this zone are defined at t2systems.com.
NS records for this zone are defined at t2systems.com.
Question and response
Question
dig mail.t2systems.com. NS
Answer
The response has no answer records.
Authority
t2systems.com. 1800 SOA frank.ns.cloudflare.com. dns.cloudflare.com. 2398751481 10000 2400 604800 1800
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0