Deleting junk emails is taking up a lot of the working week. According to a recent survey of 2,500 UK email users, carried out by Yahoo Mail, individuals are spending an average of more than an hour each week getting rid of spam - equating to six working days each year.

And users are not always adept at dealing with spam. Almost a fifth have responded to a spam message, with more than half of these doing so to unsubscribe - a worrying fact because in doing so they confirm their addresses to spammers.

These new statistics will be alarming for organisations, and indicate that staff productivity is being reduced by spam. There is clearly a need for industry to take action to educate and protect individuals to reduce the flow of junk email.

One industry initiative is the Anti-Spam Technical Alliance (Asta), which is calling on ISPs to step up their efforts to combat junk email. The group - whose members include Microsoft, Earthlink and Yahoo - released a proposal late last month for an email authentication system, detailing a series of technical measures for ISPs.

Charles Black, chief executive of business ISP Nasstar, supported Asta's proposals and said the measures could provide additional security. Citing the group's recommendation for ISPs to close open relays, he said, "If a customer is co-locating a web server, they might alter the security settings and make it open again. There's an obligation on ISPs to insist on an acceptable usage policy with customers."

However, Black said that many ISPs are already taking action to stop spam reaching their customers' inboxes - Nasstar itself uses anti-spam filtering systems from email security specialist Mirapoint. However, Black added that the cost of such services would need to be covered by customers. "We've found businesses are quite happy to pay a small additional cost for anti-spam filtering," he said. "It's cost-effective as it cuts down on staff wasting time deleting spam."

Email security experts agreed it was a good idea for ISPs to do more to fight spam. "Spam mostly originates from ISPs via home users and small businesses victimised by trojan machines and misconfigured PCs," said Paul Judge, chief technology officer at email security specialist CipherTrust. "It makes more sense for the energies surrounding preventative measures, such as these recommended by Asta, to focus on ISPs."

Judge agreed with Asta's recommendation that ISPs should implement technical measures to stop spam, and said email authentication systems would reduce the amount of spam reaching inboxes. "[Authentication systems] help identify legitimate email, which allows anti-spam technologies to be more aggressive and more effective in detecting spam," he added.

Martino Corbelli, marketing director at filtering tools company SurfControl, argued that ISPs should do a lot more to combat spam. "It is apparent that internet and email providers are not fulfilling their obligations to consumers and a drastic change in attitude is needed if this situation is to improve," he said.

Corbelli said that spammers are using increasingly sophisticated systems, so it is essential that defensive technologies keep pace. He added that there is also a role for laws to help fight junk email. "Over time, the spammers will discover new methods to get around any barriers set by ISPs," said Corbelli. "This vicious circle will continue until legislation is forcefully introduced to help stop the problem."

But CipherTrust's Judge argued that there has already been some success in the fight against spam. "The amount actually reaching inboxes is declining," he said.