Microsoft® Office Outlook® 2003 can automatically select an optimal encoding for outgoing e-mail messages. This feature increases the likelihood that when you send a message with Outlook, users receiving the message will see all the characters rendered properly, even if the users run older e-mail programs. Automatic messaging encoding results in less configuration work for administrators and a better experience for users.

Outlook scans the entire text of the outgoing message to determine a minimal popular encoding for the message. Outlook selects an encoding that is capable representing all of the characters and that is optimized so that the majority of the receiving e-mail programs can interpret and render the content properly.

This table shows a few examples of how this works.

This works for users sending Internet mail through the POP/SMTP or IMAP transport, or for messages sent through Microsoft Exchange Server 5.5 SP 1 or later.

 Note    To use the automatic message encoding feature, users sending the message must have Microsoft Internet Explorer 5.5 or later installed.

With earlier versions of Outlook, users had to manually overwrite format encoding to choose the most appropriate encoding for an individual message, but this is no longer necessary.

Disabling automatic encoding for outbound messages

By default, Outlook automatically selects the type of encoding that will be used for outbound messages once Internet Explorer 5.5 or later is installed. You can disable Auto-Select outbound message encoding with a registry key. For the following subkey, set Autodetect_CodePageOut to 0:

HKEY_CURRENT_USER\Software\Microsoft\Office\11.0\Outlook\Options\MSHTML\International

The value is a DWORD data type.

If the registry subkey is not found, if there is no value set for the registry subkey, or if the value is set to 1, Auto-Select is enabled.

You can enforce this setting by using Group Policy with the Outlook ADM file. In the Group Policy snap-in, the policy for disabling automatic message encoding is located in User Configuration\Administrative Templates\Microsoft Office Outlook 2003\Tools | Options\Mail Format\International Options. Double-click Encoding for outgoing messages, then select Disable to prevent Outlook from automatically encoding messages.

You can also set automatic encoding for outbound messages in the user interface.

To set automatic message encoding through the user interface

1. On the Tools menu, click Options, then click the Mail Format tab.
2. In the Message format section, click International Options, then select Auto-Select encoding for outgoing messages.

Setting default encoding for outbound messages

You can set a registry key to establish a default encoding for outbound e-mail messages. This encoding is used for all outbound messages if Auto-Select encoding is not enabled. This encoding is also used as the preferred encoding if the Auto-Select encoding algorithm finds multiple suitable encodings for the message. By default, Outlook sets preferred encoding to a popular Internet encoding corresponding to the active Microsoft Windows® code page of the user's computer. For example, Outlook specifies Western European (ISO) when running on Western European Latin1 Windows code page 1252.

For example, to set the default code page to be used for message encoding to Western European (ISO)," you would set Default_CodePageOut to 00006faf in the following registry subkey:

HKEY_CURRENT_USER\Software\Microsoft\Office\11.0\Outlook\Options\MSHTML\International\

This value is a DWORD data type. (See the table in the next section for a list of encodings and corresponding code pages.)

You can enforce a specific encoding by using Group Policy with the Outlook adm file. In the Group Policy snap-in, the policy for configuring encoding for all outgoing messages is located in User Configuration\Administrative Templates\Microsoft Office Outlook 2003\Tools | Options\Mail Format\International Options. Double-click Encoding for outgoing messages, then select Enabled to allow configuring the policy. Choose an encoding from the Use this encoding for outgoing messages: drop-down list, then click OK.

To set a specific encoding value through the user interface

1. Click Tools, click Options, then click the Mail Format tab.
2. In the Message format section, click International Options.
3. In the drop-down list for Preferred encoding for outgoing messages, select the encoding that you prefer.

Outlook encoding support

Outlook supports the encodings listed in the table below when sending and receiving e-mail messages.

 Note    For automatic encoding selection in Outlook to work properly, you must make sure that appropriate international support (NLS files and fonts) is installed on users' computers. For more information about enabling international support, see Preparing Users' Computers for Multilingual Capabilities in Office.

By default, automatic encoding selection in Outlook considers for detection all encodings marked Yes in the table below. All encodings in the list below are valid values to set as the Preferred encoding for outgoing messages by using the registry subkey Default_CodePageOut, described above.

Related link

Outlook 2003 provides Unicode support throughout the product. For more information about how you can define Outlook user profiles to use Unicode, see Configuring Unicode Options for Outlook 2003.