Abstract: In a processing system distributed over a large geographic area, data are transferred from one system to another by a combination of as needed basis and a continually executing background utility. To transfer voice mailboxes and voicemail processing to a newly installed or under-utilized system, a communication network is established between at least one source system and a destination system. The migration function is activated on the destination system by specifying one or more migration ranges of mailboxes. When a call is received for one of the mailboxes in the migration range(s), if the destination system does not have the mailbox information in its database, a query is sent to the source system to retrieve the mailbox information which is stored at the destination system. Messages are retrieved from the source system by the destination system using remote play capabilities.