Abstract: A unified messaging system is provided that includes two-way synchronization and replication of messages. The unified messaging system includes a workstation, a voice-mail server, and an e-mail server. The workstation may be a personal computer, for example. The workstation includes an agent to monitor messaging activities within the workstation mailbox. Also, the voice-mail server includes a proxy e-mail client (PEC) to operate and retrieve e-mail messages in the absence of the workstation. In accordance with the system and method of the invention, two-way synchronization and replication is provided. The two-way synchronization and replication operates between the workstation and the voice-mail server. Specifically, the replication operates between the e-mail store, e.g., the mailbox, of the workstation and the voice-mail store of the voice-mail server. The replication duplicates messages in each of the mailbox of the workstation and the voice-mail message store of the voice-mail server.