mx.crescentgroupltd.com has no NS records.
NS records for this zone are defined at crescentgroupltd.com.
NS records for this zone are defined at crescentgroupltd.com.
Question and response
Question
dig mx.crescentgroupltd.com. NS
Answer
The response has no answer records.
Authority
crescentgroupltd.com. 3600 SOA dns.crescentgroupltd.com. hostmaster.crescentgroupltd.com. 1305049791 43200 3600 604800 3600
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0