One morning, I rang up a spammer to complain about the emails he kept sending me. His name was Dave Mustachi; and as I was calling from London at about 9am and he lived in Florida, then five hours behind, I was delighted to catch him groggy and tired from being roused by his telephone.

"Your emails," I said to him, "are really annoying me because I've never asked for them. I have emailed you to ask to be removed from your mailing list. If you don't, I'm going to keep calling you randomly at this sort of time."

"Um, OK," he said, still half asleep, but awake enough to realise he didn't want to hear any more. "What's your email?"

I gave it to him and never received another spam I could trace back to him.

This was, however, about 10 years ago. Such an approach couldn't work now, for a number of reasons: there's much more spam, from different people; they tend not to do it on their own account; and they don't leave their phone numbers in the details that describe which domains they own. Mustachi owned one called loveofmoney.com, which is appropriate enough; there's no other reason for spamming, since it won't win you any friends.

I began musing on this point when I realised over the new year that I have long since ceased to worry about email spam. I think there are two reasons. First, there are multiple spam filters between me and the outside world: some at the companies that forward my email (Google Mail does a very good job), some on my machine, some in the email programs I use. I therefore get perhaps two spams a day - from an average of 200 predominantly generated outside my workplace. More importantly, I have come to accept spam as part of the internet landscape, like graffiti. With spam, though, you can wipe it away instantly. I certainly wouldn't waste time trying to track down a spammer now.

Yet the amount of spam seems to be declining. Postini (www.postini.com) keeps real-time data on the amount of spam it stops. A few years ago, it said spam made up around 80% of all the email circulating. When I looked last week the figure was about 60%.

While it is premature to suggest that spam is cooked, I think more people have, like me, begun to ignore it. Spam isn't the surprise it once was. Emails offering the usual three Ps - pills, pornography and poker - aren't going to find an amazed western audience, because many of the people who would want such things went online in the past few years.

Instead, the three Ps are being replaced by two others: phishing and penny stocks. But unlike the other Ps, which rely on desire, these rely on credulousness, which has a finite supply. If you don't have an eBay account but get an email saying it's been suspended, you should naturally feel suspicious.

Similarly, common sense suggests that unheard-of stock probably won't boom; and I think that after the stock market deceptions of the 1990s, people won't get fooled again. (The volume of spam touting stocks doesn't necessarily indicate that people are buying them - only that people trying to pump them have hired a spammer to spread the word.)

The other fascinating thing about this change is that it has, to some extent, fulfilled Bill Gates's prediction of January 2004 that "Two years from now, spam will be solved" (http://tinyurl.com/9bgrk). He thought it would be done by instituting tiny charges per email, or by making an email sender solve a small cryptographic puzzle, or by using a simpler system that would automatically confirm the identity of the sender.

Instead, ad-hoc filters, plus education, have done the job. While it was a nice dream that we would all install cryptographic programs to send our email, or implement a method to identify ourselves, the internet is above all about pragmatism, not idealism. It does what it can because it's a human-built object, with all the flaws that implies. Spam hasn't been solved. But I think our attitude to it could be. And that's easier to do. Then we can all - even Dave Mustachi, wherever he is - sleep easy.

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