Cached Exchange Mode If you use a Microsoft Exchange Server e-mail account, it is recommended that you use Cached Exchange Mode. A local copy of your mailbox is stored on your computer, providing you with quick access to your information regardless of changing connection types.
The information in your local mailbox is frequently synchronized with the Exchange server. If your connection to the Exchange server is interrupted, you can continue to work with your information. When a connection is restored, Outlook automatically synchronizes changes. The folders and items are once again identical.
There is no need to switch to offline
Share information In the Contacts, Tasks, Notes, and Journal panes, in the Navigation Pane, you can use the Share My links to quickly share your folder or open another person's shared folder.
Exchange Server access through the Internet (RPC over HTTP) Outlook can now connect to a Microsoft Exchange Server 2003 through the Internet without the need to use slow and sometimes unavailable virtual private network (VPN) connections. This feature allows you to remotely access your Exchange Server 2003 account from the Internet when you are working outside your organization’s firewall without any special connections or hardware, such as smart cards and security tokens.