Dear all, I've an Appian server into my intranet that need to contac

There are a few possible solutions, which depends on your network configuration. If your network admin can't offer one, you can try a Java solution.

You'll have to work with the admin who take care of application server (JBoss or WebLogic or WebSphere) to add these Java system properties to the command line that start the JVM for the app server:

http.proxyHost: the host name of the proxy server
http.proxyPort: the port number, the default value being 80.
http.nonProxyHosts:a list of hosts that should be reached directly, bypassing the proxy.

More detail here:
docs.oracle.com/.../proxies.html

If your proxy server needs user name and password to authenticate, you'll need to get a service account so you put the password in the startup script:

-Dhttp.proxyUser=someUserName
-Dhttp.proxyPassword=somePassword

I hope this helps.

Appian takes up the proxy configurations and firewall rules of the machine hosting the Web/Application server. In your case, configuring the proxy server settings for the Application server's host machine will make the internet webservice visible to Appian.

Thanks rawichp236 and raghuvarann. I'm going to try both suggestion :)