mail.grupo.host has no NS records.
NS records for this zone are defined at grupo.host.
NS records for this zone are defined at grupo.host.
Question and response
Question
dig mail.grupo.host. NS
Answer
The response has no answer records.
Authority
grupo.host. 7200 SOA ns10.hostdominicano.com. dominio.host.do. 2025112904 7200 7200 172800 38400
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0