HI all! Here is my setup:
Internet<-->Router<-->Port 25 forwarded to SpamISP Server(xxx.xxx.xxx.13)<-->SpamISP Server setup to forward to mail server<-->IIS SMTP Server setup to accept mail on port 25(xxx.xxx.xxx.15).

Sounds simple enough, but when I start the SpamISP service, nothing happens. No activity, no email, etc. I swith the port forwarding to xxx.xxx.xxx.15 and mail starts flowing in.
What more information can I give in order to get help?

lsutiger,

If no email is received while running SpamFilter, the most comon causes are:
1. A firewall/router not forwarding emails to the server running SpamFilter
2. SpamFilter is not able to bind to port 25 on the server to receive SMTP traffic. This usually occurs if there is another mail server running on the server.
 
For issue #1, you will need to reconfigure the network settingsw to route traffic properly.
For issue #2, please note that Windows will not allow two programs to use the same port to listen for traffic, so SpamFilter cannot receive emails. You can configure SpamFilter to listen for SMTP traffic on any port and/or any IP address assigned to that server. You will have to find out what other application you are running on the server, and reconfigure either SpamFilter or the other application so they do not conflict.
 
You can get an idea of what this application is by issuing the following from a DOS prompt on the server:
 
telnet xxx.xxx.xxx.13 25
 
when xxx.xxx.xxx.13 is the IP address SpamFilter is configured to listen on. The reponse SMTP banner that you will see is usually going to provide clues to indicate what that application is. If you do not receive a connection at all, that likely indicates that neither SpamFilter nor another application is listening on port 25, in which case we wold need to look at your SpamFilter's activity logfile to get a better idea of what is happening.
 
At http://www.logsat.com/sfi-spam-filter-technical-details.asp you can find several different implementation scenarios on how to configure SpamFilter and your mail server.

Ok I played a little and here's the problem I am having.

Any mail to get forwarded get a Socket Eroor 11004 -- - forwarding to:25.

Now this doesn't make much sense to me, as I am using the IP number and not the FQDN.
Also, both the Spamfilter server and the mail server are in the same domain.
I am able to telnet into the mail server from the filter server.

Umm..I may have to go through the manual again, or.....
you could explain to me how to make that happen?

Bump..

Sure thing!