Exchange email spam and virus filters

I’m currently looking at Microsoft Exchange e-mail spam and virus filters as part of my study. So I thought I would list them here so that I can look at them in more detail when I’ve got the time. Feel free to check them yourself and let me know what you think about them.

How to install SpamAssasin on Windows

A list of other Commercial Windows Spam and Anti-Virus Programs.

Linux hardware solution
Another hardware solution by Barracuda Networks
A hardware solution by Asaro International Security

Microsoft Exchange Intelligent Message Filters
Microsoft Exchange Server Intelligent Message Filter provides server-side message filtering, heuristics-based message analysis, and support for per-message spam confidence level ratings. Find out how you can reduce spam while improving productivity and trimming costs by exploring the resources listed on this page.
Note: The Exchange Intelligent Message Filter Update v1 download has been removed. A new version of this tool (Exchange Intelligent Message Filter Update v2) is available as part of Microsoft Exchange Server 2003 Service Pack 2.

Trend Micro InterScan Messaging Security Suite [] It runs on windows, and seemingly it has a really good hit rate for SPAM not tried it myself.

Another suggestion was:

You already have more than one computer on your network, so ignore exchange entirely and have another machine accepting mail for it and forwarding it on to exchange after filtering. Exchange will accept conventional email as well as it’s own odd methods.

Spamassassin is very good and can be found as part of very good cross platform packages like MailScanner. A low end machine can do a lot of filtering – and if it does get hammered the users won’t notice because exchange on the other machine will still be accepting mail at full speed and passing it on when it can.

All the alternatives to a different machine are exchange add ons which will impact on the performace of the machine to some extent simply because of what it has to do. When you get a lot of spam this will most likely result in users looking at their email client window for annoyingly long periods of time as it contacts the server for deleivery. This will result in time wasting service calls – so you could go for big hardware and good settings or shift the problem to another system where latency is not so important.