Please be aware the any applications that comes as part of MS small business server (ie. those that are bundled with SBS) where in the past different in features from the full blown server products. And unless Microsoft have changed that recently you may find that Exchange server 2003 isnt the same as the full blown Exchange server 2003 version. The problem with this is that it makes supporting the SBS and related products much harder as fewer IT professionals have the direct hands on experience with it. So I just thought you should know that and Yes! I am talking from personal experience.
**I trained on Exchange Server 5.5 and so Exchange server 2003 is now integated with LDAP and active directory (both are big subjects). Your exchange server needs to point to or map to the Force9 mailserver.
**Well done for installing the server but I have to tell you that's the easy bit, its configuring the mail server thats the real challenge. And configuring it too work as you and your company require.
**I cannot advise you on the filtering with out you telling me more about how its setup and what you want to achieve?