A method and apparatus for enabling message transmission between multiple
communication environments such as the Internet and a wireless
communications network, wherein user authentication and billing may be
performed and wherein access rights associated with one environment may
be advantageously inherited by another. The method enables the
transmission of electronic messages (such as e-mail or SMS text messages)
by registering two or more individual identities, each represented by a
communications handle (such as an e-mail address or a mobile phone
number), and by associating each of these two or more registered
identities with each other, binding them into an equivalence class of
identities, wherein one or more attributes of at least one of these
identities becomes associated with the other identity. Illustratively, a
sender-pays business (i.e., billing) model for e-mail to mobile message
transmission and access rights to an internal enterprise database from a
mobile phone are advantageously enabled.