The present invention provides a method of enabling a first user to obtain, using a business card of a second user, authority to transmit electronic mail to the second user, the business card including coded data indicative of the identity of the business card and of at least one reference point of the business card, the method including the steps of: receiving, in a computer system, indicating data from a sensing device regarding the identity of the business card and a position of the sensing device relative to the business card, the sensing device, when placed in an operative position relative to the business card, sensing the indicating data using at least some of the coded data; identifying, in the computer system and from the indicating data a request to authorise the transmission of electronic mail from the first to the second user; and recording, in the computer system, an authority allowing the first user to transmit electronic mail to the second user.