pitdc1.stargate.net has no MX records.
Question and response
Question
dig pitdc1.stargate.net. MX
Answer
The response has no answer records.
Authority
pitdc1.stargate.net. 3600 SOA auth1.dns.expedient.com. hostmaster.expedient.com. 2013061408 3600 900 604800 3600
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0