gate.forward.smtp.iad3a.emailsrvr.com has no MX records.
Question and response
Question
dig gate.forward.smtp.iad3a.emailsrvr.com. MX
Answer
The response has no answer records.
Authority
emailsrvr.com. 300 SOA ns.rackspace.com. postmaster.emailsrvr.com. 1756450505 3600 300 1814400 300
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0