Late last week RPost sued Goodmail for infringing two patents. One patent authenticates content and delivery of documents. The second verifies the message was received by the recipient.
Patent #6,182,219: Apparatus and method for authenticating the dispatch and contents of documents.

Apparatus and method for authenticating that a sender has sent certain information via a dispatcher to a recipient is disclosed. The method includes the steps of: (a) providing a set A comprising a plurality of information elements a1, . . . an, said information element a1 comprising the contents of said dispatched information, and said one or more information elements a2, . . . an comprising dispatch-related information and comprise at least the following elements: a2-a time indication associated with said dispatch; and a3-information describing the destination of said dispatch, and wherein at least one of said information elements is provided in a manner that is resistant or indicative of tamper attempts by said sender, (b) associating said dispatch-related information with said element at by generating authentication-information, in particular comprising a representation of at least said elements a1, a2 and a3, said representation comprising a set of one or more elements, each comprising a representation of one or more elements of said set A; (c) securing at least part of said authentication-information against undetected tamper attempts of at least said sender. The dispatch relates either to transmission or to manual delivery. The apparatus implements the operations of the method.

Patent #7,240,199: System and method for verifying delivery and integrity of electronic messages

A server receives a message from a sender and transmits the message to a recipient. The server normally transmits the message in a first path to the recipient. When the sender indicates at a particular position in the message that the message is registered, the server transmits the message in a second path to the recipient. The sender can also provide additional indications in the message to have the server handle the message in other special ways not normally provided by the server. After learning from the recipient or the recipient’s agent that the message was successfully received, the server creates, and forwards to the sender, an electronic receipt. The receipt includes at least one, and preferably all, of the message and any attachments, a delivery success/failure table listing the receipts, and the receipt times, of the message by the recipient’s specific agents, and the failure of other agents of the recipient to receive the message and a an encrypted hash of the message and attachments subsequently. By verifying that the digital signature on the sender’s receipt matches the digital receipt at the server, the server can verify, without retaining the message, that the receipt is genuine and that the message is accurate.

Not being a patent attorney, I don’t know how valid the infringement case is. Given the industry push for authentication; however, the lawsuit may have further reaching consequences.

Authentication • Goodmail