mailadmin.aciglobal.com has no NS records.
NS records for this zone are defined at aciglobal.com.
NS records for this zone are defined at aciglobal.com.
Question and response
Question
dig mailadmin.aciglobal.com. NS
Answer
The response has no answer records.
Authority
aciglobal.com. 300 SOA ns1.aciglobal.com. hostmaster.aciglobal.com. 2026012901 10800 3600 604800 86400
Additional
. 0 OPT ; payload 4096, xrcode 0, version 0, flags 0