I'm running Exchange 2000 behind ISA Server (Firewall).  Exchange is being published as a internal server on ISA.  All SMTP mail comes in through the ISA server and gets forwarded to the Exchange server.  Problem is ISA does not have the ability to redirect traffic to another port (i.e. port 26).  So, the scenario of having SPAMFilter listening on port 26 and then forwarding to port 25 of the mail server isn't possible.

Currently, I've gotten this setup to work with changing my server to port 26 and then SPAMFilter to port 25, but my forum boards that automatically send SMTP traffic to port 25 get stuck going through SPAMFilter, which you don't want (SPAMFilter shouldn't control outgoing mail).  The result - an error message saying RELAY e-mail not permitted (or something like that).  I guess this is because I have relay turned off on Exchange which I do NOT want to enable.

Any ideas on how to permit SPAMFilter to relay outgoing e-mail through itself?

Thanks in advance!

NJT

//you can add to SpamFilter's IP whitelist your internal class C of IPs, so that all your internal users will be able to bypass all blocking rules and will be able to relay//

don`t !

we had some lame isa server also. just buy a router, isa isn`t good.

if you put your whole cnet inplace in logsat, some annoying spambot will try to :

mailfrom: nobody@yourip or nobody@[yourip]  because logsat will bypass all rules,

and you have two way traffic in place... this will case the listme@yourip also to work,

causing a possible blacklist.

logsat and isa is dangerous, isa rewrites packets, and always does nat on the internal interface... (we name that the infernal interface from isa)

however, if you set the gateway from your exchange server to the isa server, it can sent mail trough the nat-table of the isa server.

it is also possible to run logsat ON the isa server itself, and bind the socket to 127.0.0.1,

and publish the interface with isa

The problem is not that isa cant forward the port....it is that your default smtp connector within exchange is listening on both ethernet interfaces.  You need to do these things.

1.  Create a protocol rule in ISA to enable all 25 traffic.

2.  In exchange manager go to the the smtp connectors properties.  Set the smtp connector to only listen on the INSIDE interface.  That will stop it from picking up 25 traffic on the outside interface.

3.  Create a server publishing rule in ISA to redirect all 25 traffic to the ip address of the spamfilter

4.  Stop and Restart the smtp connector.  Stop and Restart ISA services.

Let me know if you have any problems.