correo.armultis.com has no NS records.
NS records for this zone are defined at armultis.com.
NS records for this zone are defined at armultis.com.
Question and response
Question
dig correo.armultis.com. NS
Answer
The response has no answer records.
Authority
armultis.com. 300 SOA ns-cloud-d1.googledomains.com. cloud-dns-hostmaster.google.com. 419 21600 3600 259200 300
Additional
. 0 OPT ; payload 512, xrcode 0, version 0, flags 0