By default, shared mail folders are downloaded in Cached mode in Outlook 2010

By default, if a Microsoft Outlook 2010 profile is configured in Cached mode and you add another user’s mailbox or shared folder to your profile, all items in all the folders to which you have access in the shared mailbox are downloaded to your local cache. This is a change from Microsoft Office Outlook 2007, in which only shared non-mail folder items are cached by default.

For example, the following figure shows the shared Inbox folder of Guido Pica. This Inbox folder is being cached in Outlook 2010 because the status bar displays Connected when this folder is selected in the navigation pane.

This problem is caused by a change in the default shared folder caching behavior in Outlook 2010.

To change the shared folder caching behavior in Outlook 2010 to match the default behavior in Office Outlook 2007, you must add the following registry data to your Outlook 2010 client. In this situation, only non-mail folders such as the Calendar, Contacts, and Tasks folders are cached.Use one of the following methods to configure this registry data for Outlook 2010:

• Manually change the Windows Registry.
• Configure the registry by using a Group Policy setting.
• Deploy the registry data by using the Office Customization Tool.

Regardless of the method that you use, if you disable the caching of shared mail folders, the Outlook 2010 status bar displays Online when you select a shared mail folder in another mailbox in the navigation pane. This is illustrated in the following figure.


In this configuration, items in mail folders are not available when you are working offline in Outlook 2010. However, items in non-mail folders are still available when you are working offline in Outlook 2010.

Method 1: Manual modification of the Windows Registry

Important This section, method, or task contains steps that tell you how to modify the registry. However, serious problems might occur if you modify the registry incorrectly. Therefore, make sure that you follow these steps carefully. For added protection, back up the registry before you modify it. Then, you can restore the registry if a problem occurs. For more information about how to back up and restore the registry, click the following article number to view the article in the Microsoft Knowledge Base:

To change the shared folder caching behavior in Outlook 2010 to match the default behavior in Office Outlook 2007, you must add a registry value to your Outlook 2010 client. To do this, follow these steps:

1. Exit Outlook 2010.
2. Start Registry Editor:
   
   For Windows Vista and for Windows 7:
   1. Click Start
      Collapse this imageExpand this image

      
      , type regedit in the Start Search box, and then press ENTER.
      
      Collapse this imageExpand this image

      
      If you are prompted for an administrator password or for confirmation, type the password, or click Allow.
   For Windows XP:
   1. Click Start, click Run, type regedit, and then click OK.
3. Locate and then click the following registry key:
   HKEY_CURRENT_USER\Software\Microsoft\Office\14.0\Outlook\Cached Mode
   Note If the Cached Mode key does not exist, create this key by following these steps:
   1. Select the Outlook key.
   2. On the Edit menu, point to New, and then click Key.
   3. Type Cached Mode, and then press ENTER.
   4. Select the Cached Mode key and then go to step 4.
4. On the Edit menu, point to New, and then click DWORD Value.
5. Type CacheOthersMail, and then press ENTER.
6. On the Edit menu, click Modify.
7. Type 0, and then click OK.
8. Exit Registry Editor.
9. Start Outlook 2010.

Method 2: Configure the registry by using a Group Policy setting

The registry key value that is required to change the default shared folder caching behavior in Outlook 2010 can be configured by using a Group Policy setting. The default Group Policy template (Outlk14.adm) for Outlook 2010 does not contain the policy setting that controls this functionality. Therefore, you must use a custom Group Policy template to manage this functionality.

To deploy this setting by using a custom Group Policy template, follow these steps:

1. Download the following file from the Microsoft Download Center:
   http://download.microsoft.com/download/2/1/F/21FB30E6-C526-4B65-BAF1-7FE0E2252879/outlk14-DisableCachingSharedMailFolders.zip (http://download.microsoft.com/download/2/1/F/21FB30E6-C526-4B65-BAF1-7FE0E2252879/outlk14-DisableCachingSharedMailFolders.zip)
   Note The custom .adm template contains the following text.

   CLASS USER
   
      CATEGORY !!L_MicrosoftOfficeOutlookCachedSharedMailFolders
            POLICY !!L_TurnOnOffSharedMailFolderCaching
                KEYNAME "Software\Policies\Microsoft\Office\14.0\Outlook\Cached Mode"
                EXPLAIN !!L_TurnOnOffSharedMailFolderCachingExplain
                VALUENAME "CacheOthersMail"
                VALUEON NUMERIC 0
                VALUEOFF NUMERIC 1
            END POLICY
         END CATEGORY
   [strings]
   L_MicrosoftOfficeOutlookCachedSharedMailFolders="Outlook 2010 Shared Mail Folder Caching"
   L_TurnOnOffSharedMailFolderCaching="Disable shared mail folder caching"
   L_TurnOnOffSharedMailFolderCachingExplain="This policy controls the caching of shared mail folders in Outlook 2010 \n \n By default, Outlook 2010 caches shared mail and non-mail (Calendar, Contacts, Tasks) to which you have access.\n \n Enable this policy to configure Outlook to only cache shared non-mail folders. This mirrors the default shared folder caching behavior in Outlook 2007.\n \n If you disable this policy or do not configure this policy, shared mail and non-mail folders to which you have access are cached in your .ost file when you add another mailbox to your profile."
   

2. Add the Outlk14-DisableCachingSharedMailFolders.adm file to the Group Policy Object Editor or to the Group Policy Management Console.
   
   Note The steps to add the .adm file to the Group Policy Object Editor or the Group Policy Management Console vary, depending on the version of Windows that you are running. Also, because you may be applying the policy setting to an organizational unit and not to the whole domain, the steps may also vary in this aspect of applying a policy setting. Therefore, check your Windows documentation for more information.
   
   Go to step 3 after you add the .adm template to the Group Policy Object Editor or to the Group Policy Management Console.
3. In the Group Policy Object Editor or the Group Policy Management Console, under User Configuration, expand Classic Administrative Templates (ADM) to locate the policy node for your custom template. By using the custom *.adm template that is provided in step 1, this node is named Outlook 2010 Shared Mail Folder Caching.
   
   Collapse this imageExpand this image

   
4. Under Outlook 2010 Shared Mail Folder Caching, double-click Disable shared mail folder caching.
5. Click Enabled, and then click OK.
   
   At this point, the policy setting is applied on your Outlook 2010 client workstations when the Group Policy setting update is replicated. To test this change, at the command prompt, type the following command, and press ENTER:
   gpupdate /force

After you run this command, start Registry Editor on the client workstation to make sure that the CacheOthersMail registry value exists on the client, and that it has a value of 0: If you see this registry data in the registry, the Group Policy setting was already applied to this client. Start Outlook 2010 to verify that this change is implemented.

Method 3: Deployment of the registry data by using the Office Customization Tool

You can also deploy this setting by using the Add registry entries option in the Office Customization Tool (OCT). To do this, follow these steps:

Note You must have an Enterprise edition of Microsoft Office 2010 to use the OCT. If you have a Retail edition of Office 2010, you receive the following error when you try to start the OCT:

1. Click Start
   Collapse this imageExpand this image

   
   , type cmd in the Start Search box, and then press ENTER.
2. At the command prompt, type the following, and then press ENTER:
   \\Server\share\Office2010\Setup.exe /admin
3. In the Select Product dialog box, click Create a new Setup customization file for the following product.
4. Select the Office product in the Select Product dialog box, and then click OK.
5. In the navigation pane of the OCT, click Add registry entries, and then click Add.
6. In the Add/Modify Registry Entry dialog box, make the following changes, and then click OK.
   1. Root: HKEY_CURRENT_USER
   2. Date type: REG_DWORD
   3. Key: Software\Microsoft\Office\14.0\Outlook\Cached Mode
   4. Value name: CacheOthersMail
   5. Value data: 0
   The following figure displays these changes that were made in the Add/Modify Registry Entry dialog box.
   
   Collapse this imageExpand this image

   
   
   
   After you click OK in the Add/Modify Registry Entry dialog box, the OCT displays this registry data. This change is displayed in the following figure.
   
   Collapse this imageExpand this image

   
7. Complete any remaining tasks in the OCT, and then save your .msp file.
8. Deploy Office 2010 with this .msp file.

You can disable the caching of all shared folders when you are using a Cached mode profile. This includes shared mail folders and shared non-mail folders. This setting is available in the OCT and in the Group Policy template (Outlk14.adm).

The following figure shows the OCT setting that controls the caching of all shared folders in Outlook 2010.


When you use the OCT to disable this setting, the following registry key value is configured on your Outlook 2010 client. The following figure shows the Group Policy Management Editor setting that controls the caching of all shared folders in Outlook 2010.


When you use a Group Policy setting to disable this setting, the following registry key value is configured on your Outlook 2010 client.

Note This is a "FAST PUBLISH" article created directly from within the Microsoft support organization. The information contained herein is provided as-is in response to emerging issues. As a result of the speed in making it available, the materials may include typographical errors and may be revised at any time without notice. See Terms of Use (http://go.microsoft.com/fwlink/?LinkId=151500) for other considerations.