The proxy documentation states that proxies are not support for automations. How do I set up my automation and/or proxy to use the FTP Diectory trigger when a proxy is in place?

Curently when I add the FTP details to the FTP Directory Trigger and try to validate the connection i get the following error:

 Invalid - Connection attempt timed out. Verify that the port number and security type are correct.

I have tried all the combinations of secutiy settings available and get the same error each time.