The biggest problem with all of these systems is that they can't really do much about it. There's laws pertaining to what kinds of UCE (unsolicited commercial email) can be sent from within Australia and it's possible to take Australian spammers to court but the problem is two-fold:
1) Most spam comes from overseas (believe it or not, North America, because of...)
2) Most spam comes from botnets and so are untraceable to a particular 'sender'
A botnet is a collection of thousands of computers that have been compromised in some way and are now running email servers to send spam from. Not only that, but they're also used for blackmailing sites with the option of paying tens of thousands of dollars or having the site brought down (look around for articles on online gambling DDoS).
Anyway, despite their best intentions, these sorts of programs will only see a small decrease in the number of spam emails you get.
In reality, you have to just work out the best way to keep yourself 'functional'. Install a program called spambayes. It intercepts any email that comes to your computer and learns what you consider spam. What it will do is either start to just delete the spam, or attach an email header that lets your email program know that it is considered spam. Then, you can let your program do what you like with it. spambayes is free and you can get it at http://spambayes.sourceforge.net . When a spam email gets through, you can forward the email to a special address and then spambayes will know that you consider it spam, or you can use the Outlook extension to tell it so. Note that although I don't use spambayes I am in the process of converting over to it: with over a dozen active email addresses that all get parsed in to various folders depending on sender, subject and other headers, it takes a little time to add another thing to my email 'setup'
I know of several people that talk about false positives and false negatives in the range of 1 in 1,000. Remarkable.
The other thing you can do is go 'proactive': there was a group just recently that 'shut up shop' called BlueFrog. Their idea was simple. You get a piece of spam and you forward it to them. They then let every other BlueFrog user know about it (via a program running in the background) so that when they get the spam, their program automatically knows that it is spam. Now, here's the ingenious part of it: we've all been told, "don't click the link to be taken off the email list and don't follow any of the links in the spam... don't encourage them!". Instead, the BlueFrog program did just that: 'clicking' the links in the spam without you having to know it was even happening. But why?? Hundreds of thousands of 'users', wildly clicking links and all of a sudden the site is brought down and not only does the spam become ineffective but the company that used the spammer in the first place will question going down that path again...
How effective was BlueFrog? In the end, one major spammer was getting so annoyed with the BlueFrog concept that he started DDoSing (that's a distributed denial-of-service attack, effectively bringing down a server) not only BlueFrog, but other sites, too, just to try and stop BlueFrog. He basically started hitting other sites and a DNS server directly (which indirectly brought down thousands of other sites) in an effort to stop BlueFrog. It was a typical "I will keep shooting innocent victims until you stop... be it on your head" approach.
So anyway BlueFrog, being a company, stopped. However, there's a new group about to start up that is less susceptible to the last 'retaliations' and it is not being run by any one company: it's just a group of programmers. Look for the Okopipi Collective to start up soon and then we'll see some real fireworks
Last, but not least, back to the botnet issue. If you don't run antivirus, anti-spyware and a firewall, you are part of the problem. This is not even a 'maybe'. I keep my computer extremely lean and I know everything that's going on with it but I still run antivirus and anti-spyware (something like AdAware Personal). My computer is behind a separate firewall and yet I still run firewalls (eg. Sunbelt Kerio Personal Firewall... i think that's its name, it just changed recently!).
It is a fact that an unprotected computer on the internet is, on average, infected before it has time to download these programs in the first place. On average, you're looking at around 5 minutes before your computer can become part of a botnet. That's not a typo: 300 seconds and an unprotected computer is infected.
Anyway, that's that.
