The suits seek millions of dollars in damages and are part of a broader action by Amazon to crack down on e-mail forgeries, the Seattle-based online retailer said.
The companies named in the suits are pushing products including home appliances, penis enlargement pills and car warranties, according to Amazon.
Amazon and the New York attorney general's office have already settled with one of the alleged e-mail forgers. Cyebye.com of Brooklyn, New York, has agreed to pay unspecified damages and a $10,000 fine, Amazon said. Cyebye.com also must refrain from sending e-mail messages using third-party names unless it has express authorisation to do so.
Forging the sender's address in an e-mail is an online trick called "spoofing". It is a problem for Amazon and others that have a trusted domain name and use e-mail to communicate with customers. The practice is not just spam but consumer fraud, Amazon general counsel David Zapolsky said.
Amazon is working with internet service providers and others to find technical ways to make it more difficult to spoof e-mail addresses, the company said. In addition, Amazon has set up a special e-mail address, email@example.com, that consumers can use to report spoofing that involves the online retailer.
Joris Evers writes for IDG News Service