Download the Offline Address Book
This feature requires you to use a Microsoft Exchange Server 2000, Exchange Server 2003, or Exchange Server 2007 account. Most home and personal accounts do not use Microsoft Exchange. Cached Exchange Mode is recommended.
The Offline Address Book contains the properties of a user, such as e-mail addresses, that Microsoft Outlook requires in order to send an e-mail message and display information about the user. By using the Offline Address Book, Outlook does not have to connect to Exchange in order to resolve names or open the records for each user. This reduces network traffic and improves performance.
If Outlook is left running constantly in Cached Exchange Mode, it updates the Offline Address Book automatically about once a day, depending on Address Book updates on the server running Exchange. To initiate these updates manually, do the following:
On the Tools menu, point to Send/Receive, and then click Download Address Book.
Under Information to download, click Full Details or No Details.