mail.claroip.net.do has no NS records.
NS records for this zone are defined at claroip.net.do.
NS records for this zone are defined at claroip.net.do.
Question and response
Question
dig mail.claroip.net.do. NS
Answer
The response has no answer records.
Authority
claroip.net.do. 86400 SOA ns1.claro.net.do. hostmaster.claro.net.do. 2016061529 21600 900 604800 86400
Additional
. 0 OPT ; payload 4096, xrcode 0, version 0, flags 0