Google, Yahoo, AOL,, Borders Group and IAC/InteractiveCorp have been sued by Marshall, Texas-based Polaris for allegedly violating its patent for an "automatic message interpretation and routing system."

The lawsuit, filed Monday in the US District Court for the Eastern District of Texas, asks for a jury trial, damages, attorneys' fees and a permanent injunction barring the companies from continuing to use the email filtering system.

Polaris' patent, US Patent No. 6,411,947, deals with a system that can analyze incoming user emails and decide whether they can be handled automatically or need to be sent to a customer service representative. According to court documents, the patent reads, in part: "The method for automatically interpreting an electronic message may also include the step of retrieving one or more predetermined responses corresponding to the interpretation of the electronic message from a repository for automatic delivery to the source."

The lawsuit claims that the internet companies implemented this system in violation of Polaris' patent.

An attorney representing Polaris could not be reached for comment. Google could not be reached for comment. A Yahoo spokeswoman declined to comment on the ongoing litigation.

Last year, Polaris sued Kana Software for allegedly violating the same patent. The companies settled the case in March, and Kana agreed to license the technology from Polaris.