ext-ns3.morganstanley.net has no MX records.
Question and response
Question
dig ext-ns3.morganstanley.net. MX
Answer
The response has no answer records.
Authority
morganstanley.net. 3600 SOA ext-ns1.morganstanley.net. postmaster.ms.com. 39097 10800 3600 604800 3600
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0