Way to fight spam is to take away commercial gain

By ADAM GIFFORD

Spam is going to get worse before it gets better.

That's the word from Enrique Salem, chief executive of Brightmail, whose anti-spam software filters about 11 per cent of the world's email.

"In September 2001, unsolicited commercial email made up 8 per cent of all email. By July this year, over 50 per cent of email was spam," Salem said.

He said spam could be reduced only by removing the commercial imperative - making sure it does not get to the customer's in-box. He advocates regulation, education and filtering at ISP level.

TelstraClear has just installed Brightmail anti-spam and anti-virus on its servers, offering it free to all Clear.net and Paradise.net customers until the end of the year.

At that stage it will charge a fee to customers on $15 and low-use plans, and remain free for high-usage plans.

Ecommerce manager Mike Skinner said during the first few days of the service, the software was blocking between 30 and 60 per cent of messages every hour, an indicator of the cost of spam to the industry.

"It means we have to buy twice the bandwidth, twice the server infrastructure, twice the licensing costs, not to mention the support costs from dealing with the hundreds of customers calling us daily about spam," Skinner said.

TelstraClear is sidelining spam into folders where customers can access them for a month. However, given Brightmail's claim of fewer than one in a million false positives, there seems little point.

Salem said Brightmail's filters are updated every few minutes with new rules spelling out the latest spams. Multiple techniques are needed to fight Spam, and Brightmail uses most of them.

One of its main patents is for its probe network, a million decoy email addresses sprinkled around the internet on chat rooms and web sites where spammers harvest names.

"Anything which comes into the decoys is by definition unsolicited, so we can say it is spam," Salem said.

About 20 per cent of spam now involves adult content, some of it offensive. About 34 per cent offers products for sale, and 9 per cent are scams.

"Last month we blocked between six and seven billion copies of the Nigerian scam letter," he said.

Before joining Brightmail, Salem headed Symantec's anti-virus division - which is bundled in the Brightmail package. He said spamming was harder to counter than viruses.

"Viruses are written by 14- to 22-year-olds to impress their friends," he said.

"Spammers make money. They have an economic incentive to get the message through, and they work with large numbers. A spammer can send up to 200 million messages a day. One hit in half a million is significant at that volume."