Spam will be a thing of the past in two years' time, Microsoft boss Bill Gates has promised.
Spammers - senders of bulk e-mail that mostly offers dubious products or pornography - were innovative, he said.
However, a three-pronged strategy would soon stamp out the problem, he said in remarks at the World Economic Forum (WEF) in Davos.
He hailed search technology firm Google as a "great company"; its approach reminded him of Microsoft 20 years ago.
But he also predicted that Microsoft search technology would soon outpace that of its rival.
Mr Gates, by now a fixture at the annual WEF's meeting of business leaders and top politicians, said a lot of progress had been made during the past year to stop spam e-mail.
"Lots of mail you get is from people on your contact list. So what's the problem? Strangers!"
Filters could do a lot to sort spam from real mail, Mr Gates said: "Does the e-mail say it's about 'enlargement' - that might be spam."
But by adding random words in subject lines and replacing text with pictures, spammers were trickier to catch and in the long run filters would "not be the magic solution".
More promising were "human challenges" - forcing the sender to solve a puzzle, or the computer sending the e-mail to do a simple computation.
"That's easy for a machine sending a few e-mails, but gets very difficult and expensive for a computer sending lots of spam," Mr Gates said.
But ultimately, Mr Gates predicted, spam would be killed through the electronic equivalent of a stamp, also known as "payment at risk".
This would force the sender of an e-mail to pay up when an e-mail was rejected as spam, but would not deter senders of real e-mail because they could be confident that their mail would be accepted.
"Microsoft is pursuing all three approaches, and spam will soon be a thing of the past," Mr Gates asserted.
http://news.bbc.co.uk/1/hi/business/3426367.stm
Topic: Gates forecasts victory over spam (Read 1193 times)