Abstract: PBX-integrated unified messaging capabilities are provided via a switched backbone (such as the Internet) without having to install or deploy on-premise unified messaging equipment. A Corporate Communication Platform (“CCP”) typically located within a corporate subscriber's premises is integrated with the corporate subscriber's private branch exchange (“PBX”) system and coupled to a switched backbone, such as the network commonly referred to as the Internet. The CCP comprises a local mailbox database that temporarily stores voice messages and/or facsimile transmissions for and transmits messages to individual subscribers associated with the corporate subscriber. A CCP forms part of a wide-area unified messaging system, and connects to this wide-area unified messaging system via the switched backbone. The wide-area unified messaging system also comprises one or more System Communication Platforms (“SCP”).