You can store a copy of your mailbox (including your messages and other information) on your local drive in two different ways. Caching mode reduces network traffic because it doesn’t require continuous access to the network. Remote mode allows you to specify the type of connection you have, and also allows you to restrict how much information is retrieved.
To see how to back up your mailbox while in Remote or Caching mode, see Section 16.6, Backing Up Email.