Web publishing firms BlueStream Media and BVWebTies, which produce bobvila.com, are charged with violating the new act by sending the bobvila.com email newsletter to Hypertouch and its customers.
Hypertouch claims that the emails had no physical address, which is now legally required, and used fraudulent headers - the field that usually identifies the sender.
Hypertouch also alleges that the publishers sent email to randomly generated and harvested addresses, including addresses that had unsubscribed from other email lists.
Both BlueStream Media and BVWebTies have strongly denied the claim, publishing statements on their websites.
The CAN Spam Act came into effect on 1 January 2004 and, although it goes some way towards tackling spam, critics say the law does not go far enough.
Brad Templeton is chairman of the Electronic Frontier Foundation, which works to defend civil liberties online, and is also a consultant for the US Institute for Spam and Internet Public Policy.
"We're generally in opposition to spam laws, since none of them have been effective - including this one and many stronger ones - and most of them raise constitutional questions such as speech regulation," he told dotJournalism.
"A single federal law is better than having individual state laws, but spam is global - no one country's laws can do much about it directly."
The European Union introduced a directive in October 2003 making it illegal to email marketing information to individuals without their prior consent or without an existing customer relationship.
Spam is now estimated to account for as much as half of all email and recent research by the Pew Internet Project in the US showed that around one third of people have followed links in unsolicited mail.
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