Public folders are just like the calendar, contacts and email folders in your mailbox, except they're available to everyone in your workgroup. This is one of the most exciting things about using Outlook to access an Exchange server. A public folder of contacts can eliminate duplicate, conflicting phone lists. A public folder calendar can show the schedule for company events. Instant Messaging lets you send messages which appear immediately on another user's screen.
Presence information lets one user see if another is currently logged on.
This means your delegate can review and edit your calendar at any time. Delegates can also be granted access to your inbox, task list and other folders. Exchange fully supports Outlook's powerful Rules Wizard and Out Of Office Assistant. You create and modify rules easily in Outlook, then the rules are stored and processed by the server, so Outlook does not have to be running for your rules to execute. Exchange 2000 server is here.