"Since November this has been on the rise," said Neil Hammerton, managing director of secure messaging firm Email Systems. "One company we work with generally receives 24,000 emails a day. With the new spam attacks that rose to 11 million. A 450 per cent increase."
Hammerton pointed out that while larger companies can pay for spam filtering services that cope with such attacks. Educational establishments struggle. "They could be in real trouble, this is happening right now," he said.
The cause of the brute force attacks, intended to drive spam through filters by sheer weight, are bot-networks of compromised computers. "These machines have viruses on them that spread emails automatically," Hammerton said.
Last year spam reached unprecedented levels. A Frontbridge report suggested that on some days spam now accounts for over 90 per cent of all emails sent. According to Email Systems 60 per cent of all emails sent to students in 2004 were spam.