Among other things, it covers the use of an "intermediate pre-processing service [in] the electronic message delivery path" that requires changing the "Domain Name Server entry ... of the destination email server to contain an IP address of the intermediate pre-processing service."
Different methods of message preprocessing are addressed in the patent, including forwarding based on instructions stored in user profiles, forwarding parts of the e-mail message content, forwarding e-mail to wireless devices, junk e-mail filtering and virus detection.
Companies such as Postini, MessageLabs Inc., MX Logic Inc. and FrontBridge Technologies Inc. intercept inbound e-mail on behalf of customers, then filter out spam, viruses and other unwanted messages before sending the remaining messages to the customers' e-mail servers and the messages' intended recipients.
The new U.S. patent declares such configurations to be Postini's intellectual property, said Steve Frank, a partner in the patent and intellectual property group of law firm Testa Hurwitz & Thibeault LLP in Boston. "To the extent that [Postini's] competition is running preprocessing centers that intercept e-mail and does something to it, this patent has fairly broad coverage," Frank said.
Postini executives are studying the patent and considering ways to "maximize" its value to the company. In the meantime, customers and potential customers should have more confidence that the company's technology is built on a solid legal footing, said Shinya Akamine, president and CEO of Postini.
However, legal experts said Postini's patent has telltale signs of weakness and may not stand up to legal challenges.
The patent cites only other patents in the crucial "References" section, which is used to establish the originality of the patented technology compared with prior inventions, also known as "prior art."
The lack of nonpatent sources of information often indicates loose background research by the patent owners prior to filing, said Frank, who was echoed by Gregory Aharonian, publisher of the Internet Patent News Service and a critic of the Patent and Trademark Office's work on software patents.
Frequently, the best prior literature from which patentability is questioned is nonpatent documents that can be found online or at a university library, such as proceedings from the Institute of Electrical and Electronics Engineers Inc. or magazine articles, Frank said.
The lack of solid research behind the Postini patent is just an example of "major abuse" of the patent system by applicants and attorneys, who hope to slip patents by the Patent and Trademark Office, Aharonian said. "All the applicants know examiners don't have the resources to search down this stuff. At most they can search prior patents because it's all online at the [Patent and Trademark Office's Web site]. But their physical library of journals and books ... is borderline nonexistent," he said.
Postini competitors, including MessageLabs and United Messaging, now BlueStar Solutions Inc., should have an easy time demonstrating that they were selling a service similar to Postini's before the company filed for its patent, said John Levine, co-chair of the Internet Research Task Force's Anti-Spam Research Group. "If MessageLabs wanted to bust this patent, they almost certainly could," he said.
In an e-mail statement attributed to MessageLabs Americas President Jos White, the company said it has a policy of respecting the valid patent rights of others. However, White also noted that MessageLabs "pioneered the managed services model for email security, launching the first Internet-level e-mail scanning service in 1998 (as part of Star Internet, now our sister company)."
Regardless of whether the patent is ultimately upheld, it can be an effective tool against competition, Aharonian said.
"Litigation is an effective harassment tool. Once a patent is issued, it's assumed to be valid, so [Postini] can be as obnoxious as they want about enforcing the patent and not be worried about getting sanctioned [by the courts]," he said.
The effect of the patent on the growing antispam community depends on how hard Postini tries to enforce it, Levine said.
Patent disputes are often very technical and take a long time to be heard and to be resolved, which can give companies like Postini breathing room. Also, weak patents can be upheld, he added.
"It's like rolling a gigantic pair of dice," Levine said.