LONDON, England -- E-mail users on both sides of the Atlantic hoping for a legislative reprieve from spam are feeling let down.

In the past month the U.S. and UK governments have passed laws designed to thwart unsolicited e-mail marketing. Their effect, however, will be unnoticeable because of legal limitations, according to those in the industry.

"To breach the rules is not a criminal offence," says Elizabeth Dunn, a compliance manager at the Information Commissioner's Office responsible for enforcing the UK laws.

Dunn has received complaints "in the hundreds" from annoyed e-mail users disillusioned by the build-up to the law's enactment on December 12.

"We don't have the swift injunctive powers that we need to act against those abusing the medium. A lot of people assume the law is stronger than it is."

"The measures seem to be too little too late," adds Rupert Walmsley, a partner at ITC Internet which offers Web hosting along with spam filtering.

He labels the UK's Directive on Privacy and Electronic Communications as flawed because it permits spam sent to businesses providing it includes an option (however legitimate) to unsubscribe from its marketing list.

But differentiating between personal and corporate accounts is tricky.

"I could give anybody a list of a thousand e-mail addresses and if they could tell me which one was which, I would be absolutely staggered, " he says. "It's not that simple."

The U.S. law dubbed CAN-SPAM, which took effect January 1, differs by allowing spam with an opt-out function to both personal and corporate users.

Conversely, it allows states and Internet service providers to sue for e-mails not clearly identified as promotional. Despite fines of up to $2 million, marketers with dubious scruples will be enticed to move their practices to countries out of jurisdiction.

"Frankly, the amount of spam that comes from the U.S. and UK is very limited anyway," says Walmsley, whose software blocks 200 unwelcome e-mails a day from his personal inbox. "Unless there is a globally ratified act it is never going to be very effective."

Punitive action is also vital.

"We certainly don't expect an immediate drop-off," says Paula Bruening, staff council at the Center for Democracy and Technology in Washington DC, "but if there is strong enforcement we may well see some kind of decline."

Laura Yecies, senior director for e-mail at Yahoo!, which filed four lawsuits against spammers in April, considers it an enormous problem.

"Over three quarters of our users are so aggravated by deleting spam," she says, "that they think it's worse than cleaning out their toilets."

Yahoo! appears to have tackled the problem effectively with its in-house designed "SpamGuard."

Their statistics show a 40 percent rise in junk mail sent between March and September, but a 66 percent decline in spam passed through to users. Technology, evidently, has the best chance of winning this battle.

"I imagine that there will always be some junk mail, but over the next two years it will be dramatically reduced," forecasts Walmsley. "The entire industry, including Microsoft, is cracking down on spam. It will be that much harder to get through to users, and then it will not be worth the spammers time."