mx.manicaragua.com has no NS records.
NS records for this zone are defined at manicaragua.com.
NS records for this zone are defined at manicaragua.com.
Question and response
Question
dig mx.manicaragua.com. NS
Answer
The response has no answer records.
Authority
manicaragua.com. 3600 SOA dns.manicaragua.com. hostmaster.manicaragua.com. 1734587564 43200 3600 604800 3600
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0