mail.vellon.com.br has no NS records.
NS records for this zone are defined at vellon.com.br.
NS records for this zone are defined at vellon.com.br.
Question and response
Question
dig mail.vellon.com.br. NS
Answer
The response has no answer records.
Authority
vellon.com.br. 86400 SOA ns174.prodns.com.br. root.srv174.prodns.com.br. 2026030300 86400 7200 3600000 86400
Additional
. 0 OPT ; payload 4096, xrcode 0, version 0, flags 0