1. A system for forwarding an e-mail message, the system comprising: a connectivity application executable by a processor in a data network to: detect the e-mail message at an e-mail server, encrypt at least part of the e-mail message, and send the encrypted e-mail message; and a messaging centre configured to receive the encrypted e-mail message from the connectivity application and to transmit the encrypted e-mail message via an access network to a mobile terminal for decryption, the access network establishing a tunnel between the messaging centre and the mobile terminal, the mobile terminal having an e-mail address under the e-mail server and a permanent terminal identity assigned to the mobile terminal and a temporary identity in the access network, the temporary identity based on an identifier of the tunnel to the mobile terminal.