ns3.solucionwebdns.com has no MX records.
Question and response
Question
dig ns3.solucionwebdns.com. MX
Answer
The response has no answer records.
Authority
solucionwebdns.com. 300 SOA ns.rackspace.com. hostmaster.rackspace.com. 1373954451 3600 300 1814400 300
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0