Have you noticed an increase in the amount of email spam you’ve been receiving lately? Well, you’re not alone. Despite (or perhaps in spite of) Bill Gates’s breezy prediction at the World Economic Forum in January 2004 that: “Two years from now, spam will be solvedâ€?, the war is far from over. In fact, at this point, the smart money is on the spammers. They will always be more switched on than the millions of imbeciles who sustain them.

We know that a fool and his money are soon parted. But why do so many people have more dollars than sense?

Yesterday I received an email from none other than George Michael. It appears that Mr Michael is looking to build an investment in Australia, and he wants my direct number in order to furnish me with the hot details. Resisting the temptation to discover what kind of hot venture George Michael had planned for us, I binned it. There’s just no way he could ever top WHAM!

It is estimated that nine out of every ten emails are unsolicited junk. That equates to around 40 billion spam messages out there in cyberspace at any given time.

Through the second half of 2005, spam volumes actually declined. Bill Gates looked like he would be proved right. So what happened? Why are our inboxes groaning under the weight of unsolicited offers to help us make a lazy million bucks overnight, or to lose weight, or gain it, depending on the body area?

The answer lies in method. Spammers, like hackers, always seem to be one step ahead of the authorities.

Anti-spam organisations have traditionally combated spam using three filtering strategies: scanning an email’s origin, the text contained within it and the websites it links to. Since mid-2006, spammers have adopted methods aimed at circumventing these filtering techniques.

Firstly, they started sending out worms and trojans that enable them to remotely control infected computers (zombies), which they then instruct to send spam without the owners’ knowledge. These zombie armies, or botnets, allowed spammers to dramatically increase the volume of spam being pushed out while all but eliminating the chance of it being traced back to them.

Then, spammers began to avoid text filtering by including their advertisements as an attached image rather than text within the email. When anti-spam firms attempted to counter this by adopting optical character recognition filters, spammers simply introduced dots and flecks of colour to their image spam, confusing the new optical scanning technology.

Finally, the most common form of spam today does not contain links to external websites. In a technique called “pump and dump�, spammers buy an obscure stock at a very low price, promote it as the next big thing, gullible people buy it and then the spammers sell it at an inflated price, sending the stock price into free fall.

Swallow your incredulity. Pump and dump works. Why else would spammers do it? A recent study conducted by researchers from Oxford University and Purdue University found that spammers typically make between a five and six percent return from spam stock cons within two days.

Another spammer strategy you are sure to have noticed is the use of extracts from classic literature, such as “Robinson Crusoeâ€? and “Pride and Prejudiceâ€?. A few fallen literature majors aside, spammers are not known for their eloquence, and certainly not their spelling. It’s a tactic to confuse spam filters into thinking it is a legitimate email. The penny stock tips and Viagra ads are usually attached as images.

Australia has the toughest anti-spam laws in the world. But it’s one thing to police your local market and quite another to police the entire internet. Countries in Eastern Europe and Asia, where technological infrastructure has developed well beyond governing regulation, are lucrative homes for big time spammers.

It’s hard to believe that an intelligent Anthill reader could fall for a spam sting – even one veiled with the enchanting words of Henry James. But just in case, it’s good to remember that the best anti-spam filter is the one between your ears. When in doubt, delete.

Paul Ryan is an editor and senior writer at Australian Anthill.