A computer system for generating a second mail item in response to a first mail item is provided. The first mail item comprises a printed interface surface having visible information and coded data disposed thereon. The coded data is indicative of the identity of the first mail item and of a plurality of map references of the surface. The computer system is configured for: (a) receiving indicating data from an optically imaging sensing device, the indicating data including data regarding the identity of the mail item and data regarding a position of the sensing device relative to the surface, the sensing device generating the indicating data using at least some of the coded data; and (b) generating the second mail item using the indicating data from the sensing device.