Anticipation Bounces Back Electronic Return Receipt Patent as Invalid

Although patentees may delight at the allowance of broad claims in their granted patents, those same claims prove more difficult to defend against invalidity arguments at trial. A recent decision from a Massachusetts court underscores this tightrope walk, and serves as a warning that claims drafted too loosely—while allowed by the USPTO—can leave the patent at risk for invalidation by anticipation.

In this particular dispute, Sophos sought a declaratory judgment that it did not infringe four electronic messaging patents owned by RPost; RPost subsequently brought an infringement claim in a related suit. Following a joint stipulation to the dismissal of claims related to three out of the four patents, Sophos sought summary judgment that the remaining patent was invalid.

The representative claim of RPost’s patent describes a method for third-party verification of the content and delivery of an electronic message through a server, which receives a message sent to an addressee and then tags the message to indicate its registration with the third-party before transmitting the message to the addressee. Critical to the representative claim is the limitation that the server determines “if there is a particular indication present in the message that identifies the message as requiring special processing before the message is transmitted to the recipient.” During claim construction, the court applied RPost’s construction that the term “special processing” refers to processing dictated by particular indications on the message. RPost practiced its patent through its email service, which provides email senders with evidence of delivery, time of delivery, and exact message content in the form of a Registered Receipt™ email record.

Sophos contended that RPost’s patent was anticipated by two other patents. One of the two cited patents (“Dickinson”) discloses an email firewall with stored key encryption and decryption, such that the firewall comprises of a protocol by which policy managers deliver emails based on criteria such as text, size, or a specified destination. Based on these criteria, the firewall then transmits, returns, quarantines, blocks, or defers the message. Among other arguments, RPost asserted that, in Dickinson, every email undergoes extra processing (encryption, decryption) with the distinction being the type (transmit, return, quarantine, etc.) whereas, in RPost’s patent, only messages with the particular indication undergo special processing. The court separated Dickinson’s encryption and decryption step from the subsequent step of determining what to do with the message, and concluded that the latter step constitutes “special processing.” Thus, the court found RPost’s patent as anticipated by Dickinson, as RPost’s patent failed to expound on the requirements of “special processing.”

The other patent cited by Sophos (“Muldoon”) discloses a method and system for transmitting a message from sender to recipient wherein messages sent by a secure server may be marked as secure by a designator added to the Internet address or URL, or by the user’s selection of a checkbox to indicate the confidential or secure nature of the message. While RPost argued that Muldoon does not disclose special processing, but simply a re-addressing of messages, the court found that the checkbox embodiment constituted a type of “special processing.”

While it may not always be that a court will leverage the breadth of a claim—or even a broad claim construction—to find a patent invalid by anticipation, this possibility is a consideration for patentees seeking to assert their patents. Unfortunately for RPost, the Massachusetts court’s finding of invalidity was signed, sealed, and delivered.