mx2.telmexco.mail2world.com has no NS records.
NS records for this zone are defined at mail2world.com.
NS records for this zone are defined at mail2world.com.
Question and response
Question
dig mx2.pangia.biz. NS
Answer
The response has no answer records.
Authority
pangia.biz. 300 SOA mwdns10vmoc.mail2world.com. dns_admin.mail2world.net. 2015093243 3600 300 1814400 300
Additional
. 0 OPT ; payload 4000, xrcode 0, version 0, flags 0