Proxy Server

I installed MS Proxy Server 2.0 (with SP1) in NT 4.0 Server (with IIS 4.0), and installed Proxy Client in another NT 4.0 Server (with IIS 4.0, and Exchange Server 5.5), I got the following problems:
1. I can not use FTP to connect to another systemthat outside proxy.
2. I can not sent mail out through proxy server (but I can get mail that came from outside proxy).
3. I can not access to IIS (that behind proxy server)from outside proxy.
help……….. Thanks.