• Article

Configure Cached Exchange Mode in Outlook 2010

Updated: October 30, 2012

 

Applies to: Office 2010

Topic Last Modified: 2012-10-26

Banner stating end of support date for Office 2010 with link to more info

You can configure Cached Exchange Mode for Microsoft Exchange Server email accounts in Microsoft Outlook 2010.

This article describes Cached Exchange Mode and provides instructions for various ways of configuring it to work with Outlook 2010.

In this article:

  • Overview

  • Before you begin

  • Configure Cached Exchange Mode

    • To configure Cached Exchange Mode settings by using the Office Customization Tool

    • To configure Cached Exchange Mode settings by using Group Policy

    • To configure a default .ost location by using Group Policy

    • To force upgrade of non-Unicode ANSI format .ost files to Unicode

Overview

Cached Exchange Mode allows a user to continue to work with Microsoft Exchange Server account data when the connection to the Exchange server is interrupted or unavailable. When Cached Exchange Mode is enabled, Outlook 2010 works with a local copy of a user's Exchange mailbox that is stored in an offline folder (.ost) file on the user's computer and with the Offline Address Book (OAB). Cached Exchange Mode creates the .ost file, and Outlook downloads and maintains a synchronized copy of the items in all the folders of the mailbox. The cached mailbox and OAB are updated periodically from the Exchange Server computer.

Cached Exchange Mode can be configured for Exchange Server e-mail accounts only. Cached Exchange Mode is supported by all versions of Exchange Server with which Outlook 2010 can connect; that is, by Exchange Server 2003 or later versions.

If you do not configure Cached Exchange Mode options, the current state of Cached Exchange Mode does not change for existing profiles when Microsoft Outlook is upgraded to a new version. For example, if a user account was configured to use Cached Exchange Mode in Office Outlook 2003 or Microsoft Office Outlook 2007, Cached Exchange Mode remains enabled when the user upgrades the software to Outlook 2010. The location for new .ost or OAB files is the default location: For Windows XP, the location is %userprofile%\Local Settings\Application Data\Microsoft\Outlook; for Windows Vista and Windows 7, the location is %userprofile%\AppData\Local\Microsoft\Outlook.

You can configure several options for Cached Exchange Mode. These include the default .ost file location for users in your organization who do not already have .ost files for Cached Exchange Mode. If you do not specify a different .ost file location, Outlook creates an .ost file in the default location when users start Outlook in Cached Exchange Mode.

You can lock down the settings to customize Cached Exchange Mode by using the Outlook Group Policy Administrative template (Outlk14.adm). Or, you can configure default settings by using the Office Customization Tool (OCT), in which case users can change the settings.

Before you begin

Before you start deployment, review Plan an Exchange deployment in Outlook 2010 and Office Customization Tool in Office 2010 to determine which settings you might have to configure for Cached Exchange Mode.

To download the Outlook 2010 administrative templates, see Office 2010 Administrative Template files (ADM, ADMX, ADML) and Office Customization Tool (https://go.microsoft.com/fwlink/p/?LinkId=189316). For more information about Group Policy, see Group Policy overview for Office 2010 and Use Group Policy to enforce Office 2010 settings.

For more information about the OCT, see Office Customization Tool in Office 2010.

If you migrate from an earlier version of Outlook with Cached Exchange Mode enabled, determine which format your users’ .ost files are in (ANSI or Unicode). See How to determine the mode that Outlook 2007 or Outlook 2003 is using for offline folder files (https://go.microsoft.com/fwlink/p/?LinkId=159924).

Configure Cached Exchange Mode

Use the following procedures to configure Cached Exchange Mode settings.

To configure Cached Exchange Mode settings by using the Office Customization Tool

  1. In the Office Customization Tool, in the tree view, locate Outlook, click Add Accounts. In the Account Name column of the reading pane list, click the account that you want to configure, and then click Modify. The Exchange Settings dialog box appears.

    Note that in the tree view of the OCT you must click Outlook Profile and then select Modify Profile or New Profile to add an Exchange account and configure Exchange Server settings.

  2. To specify a new location for users' Outlook data files (.ost), in the Exchange Settings dialog box click More Settings, and then select Enable offline use. Enter a folder path and file name for the .ost file location. You can also enter a path in the Directory path to store the Offline Address Book files text box

  3. To enable or disable Cached Exchange Mode, or to specify default download behavior when Cached Exchange Mode is enabled, click the Cached Mode tab.

  4. Select Configure Cached Exchange Mode and then select the Use Cached Exchange Mode check box to enable Cached Exchange Mode for users. By default, Cached Exchange Mode is disabled if you do not select the Use Cached Exchange Mode check box.

  5. If you enabled Cached Exchange Mode in step 4, select a default download option on the Cached Mode tab:

    • Download only headers   Users see header information and the beginning of the message or item body (a 256 bytes plain-text buffer of information). Full items can be downloaded later in several ways; for example, by double-clicking to open the message or by clicking Download the rest of this message now in the reading pane.

    • Download headers followed by the full item   All headers are downloaded first, and then full items are downloaded. The download order might not be chronological. Outlook downloads headers followed by full items in the folder that the user is currently accessing, and then downloads headers followed by full items in folders that the user has recently viewed.

    • Download full items   Full items are downloaded. We recommend this option unless you have a slow network connection. The download order might not be chronological. Outlook downloads full items in the folder that the user is currently accessing, and then downloads full items in folders that the user has recently viewed.

  6. To turn off Headers Only mode, select the Download full items option button and clear the On slow connections, download only headers check box. The default behavior, when users have slow connections, is to download only headers. There are scenarios in which Outlook perceives that users have slow connections such as when users' data throughput is fast, or vice versa. In these situations, you might want to set or clear this option.

  7. Disable the download of shared folders as part of Cached Exchange Mode synchronizations to users' .ost files. By default, in Outlook 2010, shared mail and non-mail folders are downloaded. Downloaded shared folders increase the size of users' .ost files. Be aware that the setting Download non-mail shared folders applies to both mail and non-mail shared folders in Outlook 2010. If you want to only disable the download of shared mail folders, see step 9.

  8. Download Public Folder Favorites as part of Cached Exchange Mode synchronizations to users' .ost files. By default, Public Folder Favorites are not downloaded. As with shared folders, downloading Public Folder Favorites increases the size of users' .ost files. Also, synchronizing Public Folder Favorites causes additional network traffic that might be unwelcome for users who have slow connections.

  9. If you must disable shared mail folders (like a delegated Inbox) but want to allow the download of shared non-mail folders (like Calendar) for profiles that use Cached Exchange Mode, follow these steps:

    1. In OCT, in the tree view, locate Additional Content and then click Add registry entries.

    2. In the reading pane, click Add.

    3. Enter the following information:

      Root Data type Key Value name Value data

      HKEY_Current_User

      REG_SZ

      Software\Microsoft\Office\14.0\Outlook\CachedMode

      CacheOthersMail

      0

    4. Click OK.

To configure Cached Exchange Mode settings by using Group Policy

  1. In Group Policy, load the Outlook 2010 template (Outlk14.adm).

  2. To customize Cached Exchange Mode options, open the Group Policy Management Console (GPMC) and in the tree view expand Domains and then expand Group Policy Objects.

  3. Right-click the policy object that you want and then click Edit. The Group Policy Management Editor window opens.

  4. In the tree view, expand User Configuration, expand Policies, expand Administrative Templates, expand Classic Administrative Templates (ADM), expand Microsoft Outlook 2010, expand Account Settings, and then click Exchange. You can also expand Exchange and then click Cached Exchange Mode.

  5. In the reading pane, in the Setting column, double-click the policy that you want to set. For example, in the Exchange reading pane, double-click Use Cached Exchange Mode for new and existing Outlook profiles.

  6. Select Enabled and select an option (if appropriate).

  7. Click OK.

To configure a default .ost location by using Group Policy

  1. In Group Policy, load the Outlook 2010 template (Outlk14.adm).

  2. To configure a default .ost location, open the Group Policy Management Console (GPMC) and in the tree view expand Domains and then expand Group Policy Objects.

  3. Right-click the policy object that you want and then click Edit. The Group Policy Management Editor window opens.

  4. In the tree view, expand User Configuration, expand Policies, expand Administrative Templates, expand Classic Administrative Templates (ADM), expand Microsoft Outlook 2010, expand Miscellaneous, and then click PST Settings.

  5. Double-click Default location for OST files.

  6. Select Enabled to enable the policy setting.

  7. In the Default location for OST files text box, enter the default location for .ost files. For example:

    %userprofile%\Local Settings\Application Data\Microsoft\newfolder.

  8. Click OK.

    You can define a new default location for both Personal Outlook data files (.pst) and .ost files. After you click PST Settings in the tree view, click the Default location for PST and OST files setting in the reading pane.

To force upgrade of non-Unicode ANSI format .ost files to Unicode

  1. For users who have existing non-Unicode ANSI format .ost files, the following procedure does not upgrade ANSI .ost files to Unicode .ost files. The procedure merely creates a new Unicode .ost file for the user’s profile, leaving the original ANSI .ost files alone.

  2. To determine which format your users’ .ost files are in (ANSI or Unicode), see How to determine the mode that Outlook 2007 or Outlook 2003 is using for offline folder files (https://go.microsoft.com/fwlink/p/?LinkId=159924).

  3. In Group Policy, load the Outlook 2010 template (Outlk14.adm).

  4. Open the Group Policy Management Console (GPMC) and in the tree view expand Domains and then expand Group Policy Objects.

  5. Right-click the policy object that you want and then click Edit. The Group Policy Management Editor window opens.

  6. In the tree view, expand User Configuration, expand Policies, expand Administrative Templates, expand Classic Administrative Templates (ADM), expand Microsoft Outlook 2010, expand Account Settings, and then expand Exchange.

  7. Double-click Exchange Unicode Mode — Ignore OST Format.

  8. Select Enabled to enable the policy configuration.

  9. In the Choose whether existing OST format determines mailbox mode drop-down list, click Create new OST if format doesn't match mode.

  10. Click OK.

  11. Double-click Exchange Unicode Mode — Silent OST format change.

  12. Select Enabled to enable the policy configuration, and then click OK.

  13. Double-click Exchange Unicode Mode — Turn off ANSI mode.

  14. Select Enabled to enable the policy configuration, and then click OK.

  15. In the tree view, expand Miscellaneous, click PST Settings, and in the reading pane double-click Preferred PST Mode (Unicode/ANSI).

  16. Select Enabled, in the Choose a default format for new PSTs drop-down list click Enforce Unicode PST, and then click OK.