There may yet be hope for those who are deluged with junk email – using a new email filter they may even be able to make spammers pay them to read junk.

Software firm Anodyne has launched Stamplets, a filter system that will stop junk mail entering a user's account by filtering out any email address it does not recognise into a separate box held by the ISP.

Recipients of spam can send messages back to spammers advising that if they want their junk read, they will have to pay for the pleasure.

"You can buy a million email addresses for as little as 63p and it only takes about four hours to send those by dialup at a cost of £2.40," said Andy Dwelly, chief executive of Anodyne. "People using Stamplets are in a position to demand money for the chore of receiving unwanted mail. This makes spam uncommercial."

"The [spammer] will be notified it will have to pay to send its message through," said Simon Williams, spokesperson for Anodyne. "In most cases spammers will not bother to resend it, but will be charged in the region of £2 if they do."

ISPs Portland Communications, GuernseyNet and LocalDial have signed up to the system, but the company is in talks with several other larger ISPs it hopes will also adopt it.

"An individual can always opt out of receiving any direct marketing messages, should they choose to," said Jo Whyte, Direct Marketing Association's director of legal and public affairs, referring to the DMA's junk mail 'banned' or stop list.

For information on how to opt out of spam email altogether users should see the DMA's website.

Once the message is bounced back to the junk mailer, the sender will be directed to a payment page ( where a micropayment account must be set up.

But this part of the system will not be ready until June, so until then users will be left with a seemingly ordinary filter system.

The software will act as an add-on to whatever existing filter system is being used, stopping all emails whose addresses are not recognised, rather than filtering out specific words or phrases as many systems do.

"This is more flexible," said Williams. "Users can go to the box held on the ISP and take the emails out even after they have been filtered."

The EC estimates spam costs the internet's 410 million worldwide subscribers £6.4bn a year in connection charges alone.