mx01.vm10.com.br has no CNAME records.
Question and response
Question
dig mx01.vm10.com.br. NS
Answer
The response has no answer records.
Authority
vm10.com.br. 2821 SOA ns1.telium.com.br. suporte.telium.com.br. 2026011501 10800 3600 604800 3600
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0