Jet,

What is your end goal? Note that the Proxy Server can only proxy for one SMTP server downstream. Any human or computer program can send email to the Proxy server as long as the downsteam server accepts the message. This means you will NOT be able to relay your emails through the Proxy server unless SMTP AUTH is used and that SMTP AUTH is acceptable by the downstream server.

Please send us your end-goal, which will help me understand your situation better.