For our office we have Exchange 2003 running, and it has crap for AntiSpam (though I really did try). I turned up the sensitivity on exchange, but ended up with more false positives and very few additional spams caught. So I spent the entire day researching new AntiSpam filtering gateways. I finally decided that I would be go with postfix on the firewall machine, and have it relay to exchange. It took a bit of work, but I got it running (spent most of the evening). Turns out typo’s are a BIG problem. Anyways, if you are interested, there is a good article on howto forge about running postfix as a spamfilter on Ubuntu (but I used Debian). There were a few nuances for debian (like a missing package or two I think) but it worked out ok. For more specific info on relay and exchange (including how to build the alias map using VBS) check out this bit on Exchange Server Mailrelay. Of course the first email I received after the new gateway went up (with AS)… was spam that slipped passed the filter.
The only thing I haven’t gotten figured out is how to get SCP/SSH working w/ keys rather than passwords so I can automate the export of users from the exchange box to the firewall. I know I’m missing some small but critical piece of the puzzle. It may seem stupid to have a simple issue like this, but to be honest, I almost never (read: I actually never) use keys for SSH. The last time I did was when I was active in SF.Net projects as a webmaster, and that was probably 5 years ago. Its also possible my box is mis configured.