mailserver.webbytelecom.com.br has no NS records.
NS records for this zone are defined at webbytelecom.com.br.
NS records for this zone are defined at webbytelecom.com.br.
Question and response
Question
dig mailserver.webbytelecom.com.br. NS
Answer
The response has no answer records.
Authority
webbytelecom.com.br. 900 SOA dracarys.alares.network. ti\.inf.alaresinternet.com.br. 1 7200 900 1209600 86400
Additional
. 0 OPT ; payload 4096, xrcode 0, version 0, flags 0