The backwash from a tidal wave of spam made JOHN HARRIS pay attention to the problem of spam.

Last week, my email inbox was swamped by the backwash from a spam tsunami.

I suspected something was amiss when 500 Undeliverable email receipts arrived in my inbox on morning. Hundreds more were parked in the spam filter.

Immediately, I screamed for help from my IT-literate mate Dean Calvert who has saved my hide from numerous technology scrapes.

"Don't worry," Dean said soothingly. "Someone has just stolen your email address and is using it to send spam to millions of people on the other side of the world."

Worry was an understatement. My emotional state was flat-out panic.

Firstly, I felt violated. Since registering a URL for my business in 1995, I've worn my email address This e-mail address is being protected from spam bots, you need JavaScript enabled to view it like a favourite pair of old socks.

The thought of scurrilous spammers besmirching its reputation by offering cigarettes, cheap cosmetics, Viagra or penis extensions was like discovering that my daughter has joined One Nation.

Secondly, I was concerned this cyberspace shanghai could sabotage my ability to do business in the online world, for example, by consigning my email address to an email server "black list".

My third concern was the serious inconvenience of sorting through hundreds of unwanted Undeliverable receipts each day, a real toilet for time.

Given the only serious option was to shut down my email account, I decided to weather the storm. After several days, incoming spam returned to more normal levels.

However, as with most earthquakes, there were aftershocks. Last Friday, I received 850 Undelivered receipts from spam between midday and 5pm.

What astounds me is this onslaught was just the backwash.

The deluge filling my email inbox came only from failed spam emails, so the wicked wave that carried my name around the world must have been massive.

According to Wikipedia, the roughly 100 billion spam emails sent daily during April 2008 has levelled off in recent years (be thankful for small mercies!), with people receiving less spam due to better filtering.

The fact that spam persists in mind-numbingly large numbers is because its cost is largely borne by recipients or by people whose PCs are secretly conscripted into a "botnet" - an army of zombie computers that transmits spam or viruses across the Internet.

As a result, a single spam run can target tens of millions of email addresses, harvested from chatrooms, websites, newsgroups and detail-stealing viruses or bought from "list merchants".

So, in this face of such spam onslaughts, we can only hope for the best and prepare for the worst. 

Hoping for the best is taking the Pollyanna attitude that spammers may be eventually run out of business. After all, Wikipedia claims that 80 per of spam is sent by fewer than 200 spammers.

Preparing for the worst involves making sure your computer has an anti-virus and anti-spam scanner that is regularly updated. Common brands such as CA, Norton, McAfee or Kaspersky are available from computer stores or online, but you must remember to keep it current.

Without protection, you leave your computer open to make the spam problem even worse.