mail1.correonegocios.com has no NS records.
NS records for this zone are defined at correonegocios.com.
NS records for this zone are defined at correonegocios.com.
Question and response
Question
dig mail1.correonegocios.com. NS
Answer
The response has no answer records.
Authority
correonegocios.com. 900 SOA dns1.triara.com. hostmaster.triara.com. 2007051987 10800 3600 604800 3600
Additional
. 0 OPT ; payload 4096, xrcode 0, version 0, flags 0