OL97: What Are Offline Folders and How Do You Use Them?

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When you use Microsoft Outlook 97 with the Microsoft Exchange Server Information Service, you have the ability to work with folders "offline." That is, you can use the contents of a folder without a network connection, which is beneficial for remote users. This article discusses how you can create, use, and synchronize offline folders.


Offline folders are the quickest and easiest way to work offline with Microsoft Exchange Server. Offline folders make it possible to take a folder from the Exchange Server location, work with the contents of the folder and when connected to the network, update (synchronize) the folders to make them identical.

Offline folders are stored in an offline folder file (OST). This file is located on your computer hard disk. The default location for the OST is your current Windows folder and is available even when the network is down. Like Personal Folders (PST), the OST can be compacted to save space on your computer.

The difference between an Offline Folder file and a set of Personal Folders is that the Offline Folder file starts as a mirror image of your folders on the Exchange Server and works in conjunction with the Server during synchronization. A set of Personal Folders, on the other hand, is simply a storage location on your local disk or on a server other than the Exchange Server.

When working offline, you can add, delete, and modify the contents of an offline folder exactly as you do with a folder on a server. For example, you can change and move items in your offline Inbox, send messages that are placed in your offline Outbox, and read your offline public folders. In the meantime, information on the server is still processing. You will continue to receive new messages in your Mailbox while other users can add, delete, and change items in public folders. However, you will not be aware of these changes on the server until you connect to the network.

When you need to update the contents of the Offline folder and its corresponding server folder so that they are identical, you synchronize the folders and then continue to work offline. The Synchronize command (on the Tools menu) connects to the server through Dial-Up Networking, copies the changes made in each folder to the other folder, and then disconnects. Any item that you delete from either the offline folder or the corresponding server folder will be deleted from both after synchronization.

NOTE: Offline folders are only available with Microsoft Exchange Server.

Creating an Offline Folder File

To create an offline folder file, follow these steps:
  1. On the Tools menu, click Services.
  2. In the Services dialog box, select Microsoft Exchange Server, and then click the Properties button.
  3. In the Microsoft Exchange Server dialog box, click the Advanced tab, and then click the Offline Folder File Settings button.
  4. In the Offline Folder File Settings dialog box, in the File box, type the path to the file you want to use as the offline folder file.
  5. If the message stating that the "<path><filename>.ost could not be found. Would you like to create it?" appears, click the OK button.
  6. Click OK and OK.
NOTE: The client must be connected to the Exchange Server for the initial creation and synchronization of the Offline Folder file.

All of the standard Outlook folders (Inbox, Outbox, Deleted Items, Sent Items, Calendar, Contacts, Journal, Notes, and Tasks) on the Exchange Server are now ready for offline use. You cannot selectively choose which will be available for offline use and which will not be available. The exceptions to this are Public Folders and any user defined folders. To set Public Folders for offline use, see the Working with Public Folders Offline section later in this article.

To set any user-defined folders for offline use, follow these steps:
  1. Right click on the user-defined folder and click Properties.
  2. Click the Synchronization Tab and select "When offline or online" from the "This folder is available" section.
  3. Click OK.
You cannot use an OST file that had previously been used with a different mailbox. Doing so produces the following error message:
The file <filename>.ost cannot be accessed because it has been configured for use with a different mailbox.
NOTE: When logging into Windows, you cannot press ESCAPE when prompted for the Windows password. If you do, you will not be able to access the OST because the proper credential information has not been supplied. This is a security feature.

Working with Public Folders Offline

To work with public folders offline, follow these steps:
  1. Using the right mouse button (right-click), click the public folder that you want to work with, and click Copy "<FolderName>" on the shortcut menu.
  2. In the Copy Folder dialog box, move to your Favorites Folder, and click OK.
  3. From your Favorites Folder, right-click the newly copied folder, and click Properties on the shortcut menu.
  4. Click the Synchronization Tab and select the "When Offline or online" option under the "This folder is available" section.
  5. Click OK.
Your Public Folder is now ready for offline use. Each folder that you copy to your Favorites Folder can now be selectively set for offline use.

To synchronize offline folders, use one of the following methods.

NOTE: When you synchronize, a log file appears as a message in your Deleted Items folder. This log file contains information such as the time you synchronized, the names of the folders synchronized, and the number of items added.

Synchronizing a Specific Folder

To synchronize a specific folder, click the folder you want to synchronize, click Synchronize on the Tools menu, and then click This Folder.

Synchronizing All Folders

To synchronize all your offline folders, on the Tools menu, click Synchronize and then click All Folders.

Automatically Synchronizing All Folders When You Quit Outlook

To automatically synchronize all folders when you quit Outlook:
  1. Click Options on the Tools Menu.
  2. Click the General tab and click to select "When online, synchronize all folders upon exiting."
  3. Click OK.
All folders which are set to be available while offline will now be automatically synchronized when you quit Outlook. It is important to Synchronize and download the Address book before you logoff from your Exchange Server when going on the road. This is particularly important when going on the road for the first time. This will ensure that all your offline folders will be updated before you leave.

To download your address book, use the following steps:
  1. Click Synchronize on the Tools menu and select Download Address Book.
  2. Select to either Download the offline address book with or without details information and click OK.
Note that the Download Offline Address Book dialog contains information concerning the ramifications of downloading without detail information.

NOTE: Outlook's Remote Mail feature is not available if you are set for Offline Folder Use. For more detailed information about Remote Mail and how to use it, please see the following article in the Microsoft Knowledge Base:
162046 OL97: Remote Mail, Offline Folders, and Working Offline


Article ID: 161725 - Last Review: January 19, 2007 - Revision: 1.1
  • Microsoft Outlook 97 Standard Edition
kbinfo KB161725
Retired KB Content Disclaimer
This article was written about products for which Microsoft no longer offers support. Therefore, this article is offered "as is" and will no longer be updated.

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