staging.whyy-lb.dca.net has no MX records.
Question and response
Question
dig staging.whyy-lb.dca.net. MX
Answer
The response has no answer records.
Authority
whyy-lb.dca.net. 28800 SOA ns1.dca.net. hostmaster.dca.net. 2012031900 10800 3600 604800 86400
Additional
. 0 OPT ; payload 4096, xrcode 0, version 0, flags 0