A Slave workgroup is a workgroup that has been referenced by another workgroup. The latter workgroup is termed the master workgroup. If the master workgroup chose to replicate the data in the slave workgroup asynchronously, then data synchronisation is not immediate. Instead, a command remains in the slave workgroup, waiting to be processed. In order to process the command, the slave workgroup must process commands. When the slave workgroup processes commands, it updates itself with any changes sent by the master workgroup including delivery of any mail sent by a user in the master workgroup to a user in the slave workgroup. The slave workgroup also prepares any requests made by the master workgroup for changes to the slave workgroup's data since the last synchronisation.