Patent ID: 8429083

Claim:
A computer-implemented method, comprising: a computer system, which includes one or more processors, generating non-display stamp information for an electronic message, the electronic message being sent by a sender and addressed to a recipient; the computer system associating the non-display stamp information with the electronic message; the computer system receiving a request from the recipient, the request requesting a determination of whether the non-display stamp information represents a valid stamp that is associated with the electronic message; and the computer system determining, in response to the request, whether the non-display stamp information that is associated with the electronic message represents a valid stamp, and: if the non-display stamp information that is associated with the electronic message does represent a valid stamp, the computer system sending a first type of response to the recipient, the first type of response indicating to the recipient that the non-display stamp information does represent a valid stamp, the first type of response causing a user interface, that is associated with the recipient and that is configured to display representations of electronic messages received by the message recipient, to display a representation of the electronic message in a first manner; and if the non-display stamp information that is associated with the electronic message does not represent a valid stamp, the computer system sending a second type of response to the recipient, the second type of response indicating to the recipient that the non-display stamp information does not represent a valid stamp, the second type of response causing the user interface to display a representation of the electronic message in a second manner that is visually distinct from the first manner.