mail.nfinitcloud.com has no NS records.
NS records for this zone are defined at nfinitcloud.com.
NS records for this zone are defined at nfinitcloud.com.
Question and response
Question
dig mail.nfinitcloud.com. NS
Answer
The response has no answer records.
Authority
nfinitcloud.com. 300 SOA ns1.americanis.net. support.americanis.net. 2738613777 10800 3600 432000 86400
Additional
. 0 OPT ; payload 4096, xrcode 0, version 0, flags 0