mail.llevon.com.br has no CNAME records.
Question and response
Question
dig mail.llevon.com.br. NS
Answer
The response has no answer records.
Authority
llevon.com.br. 10800 SOA ns10.llevon.com.br. servidores.llevon.com.br. 2026020203 3600 1800 1209600 86400
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0