The US is still the worst offender when it comes to harbouring email spammers, but Europe and China are set to overtake it unless ISPs take greater action, according to research.

Some 23 per cent of spam is sent via ISPs in the US, but this figure has reduced significantly in the past two years because of the partial success of legislation such as the Can-Spam Act.

The research from internet security firm Sophos shows that although the US sent out more than half of all spam emails in

the world two years ago, China now sends out 21.9 per cent, and looks set to top the league.

France, Poland, Spain, Germany and the UK collectively distribute 16.3 per cent of all corporate spam emails.

Graham Cluley, senior technology consultant at Sophos, says a combination of international co-operation, legal action, technology and user education is needed to stamp out spam.

‘We are seeing spammers being brought to justice in the US, but they can be based anywhere in the world,’ he said.

In the UK, IT experts and business lobby groups such as the CBI have criticised lack of government regulation and prosecution of spammers.

In February, the UK spam watchdog the Information Commissioner’s Office admitted that it had not prosecuted any spammers in the previous year, despite receiving 364 complaints (Computing, 9 February).

Richard Cox, chief information officer at anti-spam campaign group Spamhaus, says the problem in the UK is getting worse, with spammers infecting broadband-connected computers so they can take control of machines to distribute junk email.

‘My biggest worry is the number of people driving botnets in the UK that are controlled by online organised crime gangs: the new mafia,’ he said.