A federal court in California has upheld the validity of a key RPost patent reinforcing the company's claims to own the technology for registered, legally recognized, court-admissible evidence of e-mail content and delivery going back to 1995.

RPost's 35 patents, granted in 21 countries, broadly cover verifiable proof of e-mail delivery and value-added outbound e-mail processing.

On December 27 the District Court for the Central District of California granted RPost a summary judgment finding its US patent 6,182,219 valid.

The decision is a lead-up to RPost's infringement suit against Trustifi Corporation but the 20-page ruling is expected to impact the suits RPost also has pending against Swiss Post, Canada Post, Adobe-Echosign, DocuSign, Zix Corporation, RightSignature, Farmers Insurance and Telarix, among others. They are all being sued for treading on ‘219 as well as other RPost patents.

RPost has asked federal courts in California, Texas and Virginia, where the suits were lodged, to issue injunctions preventing these companies from operating services that infringe RPost patents.

The Trustifi infringement case will be heard first. A jury trial is set to start in June. Whether Trustifi will be found to infringe remains to be seen. RPost couldn't get a summary judgment for its claims that Trustifi infringes ‘219 from the California court.

The ruling it did get - which denied Trustifi a summary judgment that ‘219 is invalid while simultaneously granting RPost a summary judgment that it is valid - says Trustifi failed to marshal "clear and convincing evidence" of prior art that would knock the patent out of the box on the grounds of either anticipation or obviousness. It also says that just because the US Patent and Trademark Office agreed to re-examine the patent "does not establish a likelihood of patent invalidity."

The ‘219 patent covers an "Apparatus and Method for Authenticating the Dispatch and Contents of Documents." That means a sender can prove that specific information, including e-mail, was sent at a specific time to a specific receiving party and authenticated by a disinterested third party.

Trustifi's allegedly infringing authenticating widgetry is called Trustifi Postmarked Email (TPE), which is a repackaging of the United States Postal Service's Electronic Postmark licensed through the commercially unsuccessful Authentidate Holding.

RPost CEO Zafar Khan says the decision "should serve as a notice to those companies that choose to steal RPost patented technologies and offer them in the market as if they were their own innovations. Whether they are commercial operations of big foreign governments or small technology companies looking for a go-to-market short cut, we will vigorously defend all of our intellectual property, everywhere."

The caveat extends to companies that may be integrating with technologies of dicey heritage. RPost recently opened an Apps Marketplace to showcase the implementation of its proprietary technologies integrated into different platforms.