To determine whether to use Unicode mode or non-Unicode (ANSI) mode, Outlook evaluates a set of requirements and options. One requirement for Unicode mode is that users must have Exchange 2000 or later accounts. Outlook also checks the Unicode or ANSI formats of users' Offline Store (OST) files and the default archive files. Finally, Outlook checks the format of users' PST files that are used as a delivery location (if any).

Caution:
Switching between Unicode mode and non-Unicode mode (ANSI) can cause data loss in multilingual text fields or prevent text from being readable. For this reason, users who begin using Outlook in Unicode mode should continue to use Unicode mode.

If you want to encourage users in your organization to use Unicode for Outlook, you can deploy Outlook so users can run in Unicode mode. One deployment option is to establish an environment in which, for most users, the criteria that Outlook checks to allow Unicode mode are met. Unicode is used by default if the criteria are met, unless you set options to use ANSI. Another option is to require Unicode for Outlook usage (when supported by an appropriate Exchange Server version) by setting options that create new Unicode user files automatically, if that is necessary for Outlook to run in Unicode mode. You can also use a combination of these approaches.

If you plan to deploy Cached Exchange Mode with Outlook 2003, you might want to configure and deploy options for migrating users to Unicode mode first. Cached Exchange Mode synchronizes users' OST and Offline Address Book (OAB) files with Exchange Server data. When you deploy Unicode options to users, synchronizing OST and OAB files might also be required.

For example, Outlook files are synchronized with Exchange Server in the following Unicode deployment scenarios:

• When you deploy a new offline Outlook profile—for example, to move current offline users to Unicode mode—Outlook synchronizes OST and OAB files, after creating the new files for users as part of the new profile.

• When Outlook users are moved to an Exchange 2003 server with a Unicode OAB, the new OAB is downloaded.

In scenarios like these, you might want to wait to deploy Cached Exchange Mode until after you have deployed Unicode options for your organization. This will help minimize the load on your Exchange servers and the time users spend downloading data to their computers.

Using Unicode for messaging and other Outlook features has benefits that you might want your users to take advantage of, without mandating that everyone migrate to Unicode mode directly when Outlook 2003 is installed. To facilitate greater usage of Unicode mode, you can help provide a messaging environment configured to help Outlook run in Unicode mode.

Since Outlook uses Unicode mode by default if all criteria it looks for are met, take steps to make sure that the requirements are met, such as the following:

Using the Office Customization Tool (OCT), create a new Outlook profile to deploy to users. A new offline profile creates a new OST file for users and a new default archive file by default. Both files use the new Unicode file format.

• Ensure that in the new Outlook profile, users' Exchange accounts are on Exchange Server 2000 or later.

• Deploy Outlook to your users.

  You can deploy Outlook using your organization's standard Office deployment method.

It is straightforward to create and customize a new Outlook profile by using the OCT.

To create new Outlook offline profiles for users

1. In the OCT, in the Outlook section, on the Customize Default Profile page, click New Profile.

2. In the Profile name box, type a name for the new Outlook profile, and click Next.

3. On the Outlook: Specify Exchange Settings page, click the Configure an Exchange server connection radio button.

4. In the User Name box, leave the default user name system variable, or enter a different variable.

5. In the Exchange Server box, enter the name of an Exchange server. (The Exchange server name is replaced with the correct Exchange server when the user starts Outlook for the first time after upgrading.)

6. Click More Settings.

7. On the Microsoft Exchange Server page, select the Enable offline use check box to deploy a new OST file, and click OK.

8. Click Next.

9. After you complete all desired customizations in the OCT, click Finish to create a Setup customization file.

10. Update users' computers with the new profile.

11. For more information about configuring users' computers with the new profile by using the Setup customization file, see Run Setup for the 2007 Office system on users' computers.

There might be scenarios in which it is important that all users in an organization are migrated to use Unicode mode in Outlook when Office Outlook 2007 is installed, without modifying all users' profiles. You can enforce migrating users to Unicode by making sure that the criteria that Outlook uses for determining if users run in Outlook mode are met, or that Outlook takes steps to help ensure that Unicode file formats are used in users' profiles by creating and synchronizing new Outlook files, if necessary.

The first criterion for using Unicode mode is that users must use Outlook with Exchange Server 2000 or later.

Next, Outlook checks the format of a user's OST file to determine if the file format is Unicode or non-Unicode (ANSI). If the format of the OST file is ANSI, Outlook runs in ANSI mode. However, you can set a policy so that when Outlook checks the file format, if a user has an ANSI OST file, a new Unicode OST file is automatically created and synchronized with Exchange Server. You can define the policy so that users are prompted with a dialog box that notifies them that their new OST file is about to be synchronized with the Exchange server, so users can confirm to proceed with the update at that time. Or you can require that new OST files are created without providing users the option to defer the action.

Outlook next checks the file format for the user's default archive file, if one exists. You can also set a policy that automatically creates a new Unicode default archive file. (Users can still access ANSI archive files.) Unlike the policy that manages new Unicode OST files, you cannot provide the option for users to defer creation of a new default archive file.

If a user's mail delivery location is a PST file, Outlook checks the delivery PST file to determine if the file format is Unicode. However, you cannot require a new Unicode PST file to be created to replace the existing PST file if Outlook determines that a user has an ANSI PST file. In this scenario—where Outlook delivers PST files to ANSI and you want to require Unicode mode for users—you can instead create and deploy new profiles to users with the delivery location set to new PST files, which will be Unicode by default.

Pointing Outlook to use a new delivery PST file automatically—without users specifying the change—might lead users to believe that their existing mail has vanished. Older mail is still in the original PST file, but that file is no longer in the user's profile and is not accessible by default. Users must manually add the older PST file back to their profile to access the information. Because the PST file being removed from the user profile can be perceived as data loss by users—though the data still exists, it is not where users can readily see and access it—the option to automatically switch to a new Unicode PST is not provided.

You may want to carefully time the implementation of the policies that might create and populate new Unicode files. When Outlook creates and synchronizes new Unicode OSTs and default archive files, users must wait for server data to download. You should also make sure that users have synchronized with Exchange Server prior to the new policies taking effect. Local changes that are not synchronized—such as e-mail messages in a user's Outbox or updates to Contacts information—are lost.

When you use the Microsoft Windows drag-and-drop feature to drag an Outlook item to the Windows desktop, the format of the file that is automatically created is Unicode by default. You can configure a default option by using the Office Customization Tool (OCT) to use ANSI for the message format instead of Unicode.

You can lock down the settings to customize this option by using the Outlook Group Policy template (Outlk12.adm). Or you can configure default settings by using the Office Customization Tool, in which case users can change the settings. The OCT settings are in corresponding locations on the Modify user settings page of the OCT.

The Outlook template and other ADM files can be downloaded from 2007 Office System Administrative Templates (ADM) on the Microsoft Download Center.

To use Unicode format for message files that are dragged to the desktop from Outlook

1. In Group Policy, load the Office Outlook 2007 template (Outlk12.adm).

2. Under User Configuration\Administrative Templates\Microsoft Office Outlook 2007\Tools | Options\Other\Advanced, double-click Use Unicode format when dragging e-mail message to file system.

3. Click the Disabled radio button to enforce using ANSI format instead of Unicode format for e-mail messages dragged to the file system.

4. Click OK.