You receive insufficient memory errors when you expand a mailbox or public folder in Outlook

Original KB number:   2968387

Symptoms

When you expand a mailbox or public folder (except for the Inbox) in Microsoft Outlook or select Address Book on the toolbar, you may receive one of the following errors:

Cannot display the folder. There is not enough free memory to run this program. Quit one or more programs, and then try again.

Cannot expand the folder. There is not enough memory available to perform the operation.

The address list could not be accessed. You need more memory or system resources. Close some windows and try again.

When you receive one of these errors, outgoing mail may become stuck in the Outbox folder and may not be sent until you restart Outlook.

Cause

This problem occurs when your Outlook messaging profile includes a Microsoft Exchange account that is configured to use Cached Exchange Mode, the Download Public Folder Favorites option is enabled, and you have lots of cached public folders. Usually, this problem occurs when you have more than approximately 1,000 public folders, or when the cached public folders consume one gigabyte of space.

Resolution

To prevent this problem, either disable the Download Public Folder Favorites option, or keep the number of cached public folders favorites to fewer than 1,000. If the issue continues to occur with fewer than 1,000 public folder favorites, reduce the number of folders until you stop receiving the error or errors. You can typically reduce the number of public folder favorites by deleting them by using the Outlook client. However, in some cases in which you have too many public folder favorites, you may be unable to delete the folders by using the Outlook client because the error occurs when you select the public folder Favorites folder. If this occurs, you can delete the public folder favorites by using MFCMapi instead.

To resolve this issue by disabling the Download Public Folder Favorites option, follow these steps:

1. In Outlook, select File, select Account Settings, and then select Account Settings.

2. Select your Microsoft Exchange account, and then select Change.

3. Select More Settings.

4. On the Advanced tab, clear the Download Public Folder Favorites check box.

5. Select OK.

6. You are prompted to restart Outlook for these changes to take effect. Select OK.

7. Select Next, select Finish, and then select Close.

8. Exit Outlook, and then restart Outlook.

To delete the public folder favorites by using MFCMapi, follow these steps:

1. Download MFCMAPI.

2. Run MFCMAPI.exe.

3. On the Session menu, select Logon.

4. Select your Outlook profile name, and then select OK.

5. In the top pane, locate the line that corresponds to your mailbox, and then double-click it.

6. In the navigation pane (left-side pane), expand Root - Mailbox, and then select the Shortcuts folder.

7. In the details pane (right-side pane), locate the PR_FOLDER_CHILD_COUNT properties. The Value column contains the number of public folder favorites.

8. If you want to delete all your public folder favorites, follow these steps:

   1. In the navigation pane. right-click the Shortcuts folder, select Advanced, and then select Empty items and subfolders from folder.

      

   2. Keep the default options, and then select OK.

9. If you want to delete specific public folder favorites, follow these steps:

   1. In the navigation pane, expand the Shortcuts folder, right-click the Public Folder favorite that you want to delete, and select Delete folder.

      

   2. Keep the default options, and then select OK.