How to implement a policy to control PST use and creation in Microsoft Outlook

• Applies to:

  Outlook for Microsoft 365, Outlook 2013, Outlook 2010, Outlook 2007

Introduction

In Microsoft Outlook, users can create PST files or add new items to existing PST files. This article describes how to control these behaviors as an administrator.

Procedure

Important

Follow the steps in this article carefully. Serious problems might occur if you modify the registry incorrectly. Before you modify it, back up the registry for restoration in case problems occur.

Prevent users from adding new data or content to an existing .pst file

To prevent users from adding new data or content to an existing .pst file, add the PSTDisableGrow registry entry, and then set the value to 1. To do this, follow these steps:

1. Open Registry Editor.

2. Locate and select the following registry subkey. You have to create the key if it does not exist.

   Type	Registry path
   Group Policy	HKEY_CURRENT_USER\Software\Policies\Microsoft\Office\xx.0\Outlook\PST
   Office Customization Tool (OCT)	HKEY_CURRENT_USER\Software\Microsoft\Office\xx.0\Outlook\PST

   Note

   The xx.0 placeholder represents the Outlook version (16.0 = Outlook 2016 and Outlook for Microsoft 365, 15.0 = Outlook 2013, 14.0 = Outlook 2010, 12.0 = Outlook 2007).

3. On the Edit menu, point to New, and then select DWORD Value.

4. Type PSTDisableGrow, and then press Enter.

5. Right-click the PSTDisableGrow registry entry that you created, and then select Modify.

6. In the Value data box, type 1, and then select OK.

The PSTDisableGrow registry entry can be set to the following values.

Value	Description
0	User can add new items to an existing .pst file. This is the default value.
1	Use cannot add new content or data to an existing .pst file.

Prevent users from adding new .pst files

To prevent users from connecting a .pst file to Outlook, add the DisablePST registry entry, and then set the value to 1. To do this, follow these steps:

1. Open Registry Editor.

2. Locate and select the following registry subkey. You have to create the key if it does not exist.

   Type	Registry path
   Group Policy	HKEY_CURRENT_USER\Software\Policies\Microsoft\Office\xx.0\Outlook
   Office Customization Tool (OCT)	HKEY_CURRENT_USER\Software\Microsoft\Office\xx.0\Outlook

   Note

   The xx.0 placeholder represents the Outlook version (16.0 = Outlook 2016 and Outlook for Microsoft 365, 15.0 = Outlook 2013, 14.0 = Outlook 2010, 12.0 = Outlook 2007).

3. On the Edit menu, point to New, and then select DWORD Value.

4. Type DisablePST, and then press Enter.

5. Right-click the DisablePST registry entry that you created, and then select Modify.

6. In the Value data box, type 1, and then select OK.

The DisablePST registry entry can be set to the following values.

Value	Description
0	Users can add .pst files. This is the default value.
1	Users cannot add .pst files. However, in scenarios in which a .pst file was connected to Outlook before this registry value was added, the existing .pst file will still be connected. No new.pst files can be added.
2	Users can add only exclusive sharing .pst files, such as SharePoint .pst files.

More information

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