mx.acs-intl.us has no NS records.
NS records for this zone are defined at acs-intl.us.
NS records for this zone are defined at acs-intl.us.
Question and response
Question
dig mx.acs-intl.us. NS
Answer
The response has no answer records.
Authority
acs-intl.us. 3600 SOA dns.acs-intl.us. hostmaster.acs-intl.us. 1620452864 43200 3600 604800 3600
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0