mail.server.odontolaboral.com.do has no NS records.
NS records for this zone are defined at server.odontolaboral.com.do.
NS records for this zone are defined at server.odontolaboral.com.do.
Question and response
Question
dig mail.server.odontolaboral.com.do. NS
Answer
The response has no answer records.
Authority
server.odontolaboral.com.do. 86400 SOA ns181224129103.a2dns.com. root.server.odontolaboral.com.do. 2026020100 3600 1800 1209600 86400
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0