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Customize Outlook profiles by using an Outlook Profile (PRF) file


Applies to: Outlook 2013, Office 365 ProPlus

Topic Last Modified: 2011-11-21

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

The Microsoft Outlook 2010 profile file (.prf) allows you to quickly create Messaging Application Programming Interface (MAPI) profiles for users.

By using a .prf file, you can set up new profiles for users or modify existing profiles without affecting other aspects of your installation. You can also manually edit a .prf file to customize Outlook 2010 to include Outlook settings or MAPI services that are not included in the Office Customization Tool (OCT) user interface.

In this article:

  • Overview

  • Before you begin

  • Create a .prf file

  • Manually edit a .prf file

  • Apply a .prf file


As in earlier versions of Outlook, you can continue to use the .prf file to provide options for specifying additional Outlook settings or MAPI services and to verify account settings.

The Outlook 2010 .prf file format has changed but Microsoft Office Outlook 2007, Office Outlook 2003, and Outlook 2002 versions of the file will work with Outlook 2010. If you plan to make updates to the .prf file for the Outlook 2010 deployment, we recommend that you re-create the .prf file by using the Office Customization Tool (OCT), export the settings to a new .prf file, and then use that file to specify the additional Outlook settings or MAPI services that you need.


There is a known issue in which an additional Exchange account is added to the Outlook profile when a user who already has an exchange account in the profile is upgraded from Outlook 2003 or Outlook 2007. This issue can occur while you are upgrading Outlook and applying customizations by using a custom OCT file (.msp) or .prf file that is configured to “Modify Profile" and "Define changes to make to the existing default profile.”
To prevent multiple Exchange accounts from being created in one profile when you upgrade users to Outlook 2010, you must download and use the Service Pack 1 (SP1) version of the OCT, which is available from the Microsoft Download Center ( To update the OCT, replace the /Admin folder that is in your Office 2010 installation files or installation image with the new /Admin folder that is included in the download package. If you do not use the SP1 version of the OCT, you must create a .prf file and set the properties BackupProfile=False and UniqueService=Yes. For the steps to do this, see Multiple Exchange accounts created in Outlook 2010 with existing Outlook profiles after upgrading from an earlier Office version using a custom MSP (

Before you begin

Before you begin deployment, review Planning overview for Outlook 2010 to determine which settings you might want to configure by using a .prf file.

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


To create an Outlook 2010 .prf file, you can configure profile settings by using the OCT, and then export the settings to a .prf file. This process creates a new Outlook 2010 .prf file that includes your specifications.

You can also specify profile settings by editing an existing .prf file manually by using a text editor. This existing .prf file might be one that you created by using the OCT, or a .prf file from an earlier version of Outlook. However, the .prf file format has changed in Outlook 2010. Therefore, we recommend that you re-create the older .prf file to prevent unexpected behavior.

Create a .prf file

To create a PRF file by using the Office Customization Tool

  1. From the root of the network installation point, run the following command line to start the Office Customization Tool: \\server\share\setup.exe /admin

  2. To edit an existing customization file (.msp), in the Select Product dialog box, click Open an existing Setup customization file. Or to create a new customization file, select the Office suite that you want to customize, and then click OK.

  3. In the Outlook area, click Outlook Profile. Select how you want to customize profiles for users. To specify settings to be included in a .prf file, choose Modify Profile or New Profile.

  4. To add and configure new accounts or to modify or remove existing accounts, click Add accounts, and then click Customize additional Outlook profile and account information.

  5. Once you complete the Outlook profile configurations, in the Outlook area, click Export settings.

  6. Click the Export Profile Settings button to create a new .prf file. Enter a file name and the path on which to save the file, and then click Save.

Manually edit a .prf file

When you manually change a text file, you can introduce errors that cause Outlook to behave incorrectly. You should not edit and deploy a manually modified .prf file unless you have no other way to update user profiles. If possible, you should use the OCT to create and deploy .prf files.

To manually update a .prf file

  1. Open the .prf file by using a text editor such as Notepad.

  2. Make your changes or additions. By manually editing the .prf file, you can add any MAPI service that is supported by Outlook 2010. The .prf file includes detailed comments for each section that describe existing settings and options for modifying the file that has your updates. The file includes the seven sections shown in the following table.

    Section Description

    Section 1 – Profile defaults

    String identifiers found to the left of the equal sign (=) in this section (ProfileName, DefaultProfile, and so on) are defined in the .prf processor in Outlook and cannot be modified externally. These are default settings that are used to set up a user profile.

    For example:


    An existing profile can be either overwritten or updated when a new .prf file is executed. Several settings control how the new settings are applied:

    • The OverwriteProfile setting can be set to Yes, Append, or No. To update existing profiles, set the value to Append. This preserves the existing profile and updates the sections that have been changed. To overwrite existing profiles with a new profile, set the value to Yes. To prevent overwriting an existing profile, set the value to No.

    • The ModifyDefaultProfileIfPresent setting can be set to True or False. When set to True, Outlook will modify the default profile even if the new and existing profile names are different.

    Section 2 – Services in Profile

    This section includes the list of services to be configured in the client. The services are listed in the order in which they are added to the profile. Each service listed here is defined and referenced in Section 4.

    For example:

    [Service List] 
    ;ServiceX=Microsoft Outlook Client
    ServiceEGS1=Exchange Global Section 
    Service1=Microsoft Exchange Server

    You can add any MAPI service that is supported by Outlook 2010. The following services were supported in earlier versions of Outlook, and should not be added:

    • MS Mail

    • Symantec WinFax Lite

    • AW Fax

    Section 3 – List of Internet accounts

    Internet accounts can be POP or IMAP e-mail accounts. This section lists the Internet accounts that will be defined and referenced in Section 5.

    For example:

    [Internet Account List] 

    Section 4 – Default values for each service

    This is the section to which you can add properties or change existing property values for the services in the profile. MAPI profile properties are defined for services under each respective [ServiceN] heading. Valid Profile Property names are determined by the MAPI profile property mapping in Section 6.

    For example:


    To allow each service definition to be customized individually, you can duplicate default variables and values in Section 4 under the separate headings (Service1, Service2, and so on) for each service in the profile.

    For each service to be updated, the OverwriteExistingService setting can be set to Yes or No. Set the value to Yes so properties are re-created for that service. The default for OverwriteExistingService setting is No. If No is specified, the service will not be updated, even if new settings have been listed.

    Section 5 – Values for each Internet account

    This section defines values for the POP and IMAP e-mail accounts referenced in Section 3. Internet account properties are listed similarly to service properties, by using [AccountN] heading notations. Valid Profile Property names are determined by the MAPI profile property mapping in Section 7.

    For example:

    AccountName=POP Account

    Section 6 – Mapping for profile properties

    You typically do not modify existing entries in Sections 6 and 7. These sections define mappings for information that is defined elsewhere in the file to registry key settings. However, if you define new services in the .prf file, you must add the appropriate mappings for those services to Sections 6 and 7.

    Section 6 lists each service name that Outlook supports and the numeric MAPI profile property values that correspond to the registry keys that the Outlook .prf processor implements when storing the profile properties.

    All values listed in Section 6 map directly to HKEY_CURRENT_USER\Software\Microsoft\Windows NT\CurrentVersion\Windows Messaging Subsystem\Profiles\ProfileName registry entries, where ProfileName is replaced by the name of the corresponding profile. When a service is added, a new GUID is created for it.

    The Exchange sections have predefined GUIDs assigned because they are unique services. A service can have more than one section GUID. Therefore, the number of GUIDs in the registry does not always correspond to the number of services that Outlook has “registered.”

    Section 6 includes several mapping strings for profile properties. This makes the .prf file very flexible. If you know the specific property that you want to change, you can write a .prf file that has the appropriate properties in Section 6 and the appropriate corresponding property values in Section 4, which allows the property to be deployed.

    Section 7 – Mapping for Internet account properties. DO NOT MODIFY.

    This section corresponds to the mapping for the specified [AccountN] accounts in Section 5. There is a GUID in the Profile section (GUID 9375CFF0413111d3B88A00104B2A6676) that expands and lists DWORD data types. Each of these DWORD types corresponds to an Account in the .prf file. There might be more than one DWORD registry key per account. Therefore, as with Services, there is not a one-to-one mapping for Accounts.

    The same registered property types are present here as are listed in Section 6, and the same notation is provided for MAPI profile property mapping. The separate sections (2, 4, 6 and 3, 5, 7) are an artifact of Internet Only (OMI) and Corporate Workgroup modes. Because OMI was stored in a different location in the registry for earlier versions of Outlook, and migration code depends on values being in a consistent format, you should not modify this section even if you are deploying updates for a version of Outlook later than Outlook 2000.

  3. Once you have completed your changes, save the file. For instructions about how to apply the .prf file, see the following section, Apply a .prf file.

Apply a .prf file

You can apply a .prf file in several ways to update Outlook profiles.

To apply a .prf file by using the customization file

  1. From the root of the network installation point, run the following command line to start the OCT: \\server\share\setup.exe /admin

  2. To edit an existing .msp file, in the Select Product dialog box, click Open an existing Setup customization file. Or to create a new customization file, select the Office suite that you want to customize, and then click OK.

  3. In the Outlook area, click Outlook Profile. Select Apply PRF, and then browse to the file.

  4. On the File menu, click Save to save the .msp file.

  5. Exit the OCT.

  6. Put the .msp file in the Office installation source \Updates folder.

  7. Install Office 2010 from the original installation source.

To apply a .prf file by using other options

  • Specify the .prf file as a command-line option for Outlook.exe to import a .prf file without prompting the user. For example: outlook.exe /importprf \\server1\share\outlook.prf.

  • Specify the .prf file as a command-line option for Outlook.exe, but prompt the user before importing the .prf file. For example: outlook.exe /promptimportprf \\localfolder\outlook.prf. If you put the specified .prf file in a shared folder on a network, the settings might not be applied if the file is not found or is not available when Outlook runs.