A system and method for the provisioning of subscribers of a first communications network, such as a voice messaging system, to a second communications network, such as an e-mail messaging system. An exemplary system and method is described in which subscribers to a universal voice messaging system (UVMS) which handles voice and fax messages are provisioned to a message handling system (MHS) which handles e-mail messages. A message handling system provision service (MPS) provides the provisioning of the first network's subscribers to the second network. Thus, data is provisioned at a first messaging system and is forwarded to a second messaging system. Additional data for the subscriber from the second messaging system is returned to the first messaging system.