Lawmakers at the lower house of the US Congress passed on Saturday the Can-Spam Act of 2003 by a vote of 392-5, allowing millions of Americans to block junk mail, better known as spam, from flooding their computers.
The Senate passed a similar piece of legislation last month and is largely expected to accept changes introduced in the House bill.
"For the first time during the Internet-era, American consumers will have the ability to say no to spam," Republican lawmaker Billy Tauzin said.
"What's more, parents will be able to breathe easier knowing that they have the ability to prevent pornographic spam from reaching defenceless, unsuspecting children," he said.
The bill gives Internet users the right to opt-out of all commercial e-mail traffic, prohibits the sending of fraudulent spam and introduces stiff fines for illegal spam messages.
In addition, people who flood the Internet with unsolicited advertisements can be sued under the legislation for damages of up to $2 million, an amount that can be tripled to $6 million for intentional violations.
Pornographic e-mails will have to carry special electronic labelling so they could be easily filtered out by personal computers.