We have used Flex messaging in an Flex/Java based application
(Flex 2.0.1). The messaging works fine in our production/QA server.
But when we deployed the application to the production server,
which can be accessed by a public IP, the messaging feature failed.
Nevertheless, if we connect the production server using a VPN
connection and use an internal IP to run the application, the
messaging is working but does not work when the same application is
accessed using the public IP.
We have used rtmp channel for messaging and we have opened
the port used in both the public IP as well as the internal IP.
Can you please try recompiling/cleaning your Flex project
with your server name replaced in the end point URL of your
services-config.xml. i.e change the end point URL to
rtmp:servername:2037 and clean your Flex project.