mta04.redebrasil.com.br has no CNAME records.
Question and response
Question
dig mta04.redebrasil.com.br. NS
Answer
The response has no answer records.
Authority
redebrasil.com.br. 900 SOA ns2.redebrasil.com.br. root.redebrasil.com.br. 2026022001 900 900 900 900
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0