There are three language settings that you can configure for Outlook Web Access. 

• The logon and error language setting applies to individual Outlook Web Access virtual directories. The logon and error language is the language that will be used for errors and the forms-based authentication logon page. If a value is not set for this language, the default value is 0. This means that the default logon and error language is not defined. If the logon and error language is not defined, Outlook Web Access will default first to the language set on Internet Explorer on the client computer. If the language set on Internet Explorer on the client computer is not supported by Outlook Web Access, Outlook Web Access will use the language of the Client Access server.
  
• The default client language setting applies to individual Outlook Web Access virtual directories. The default client language is the client language that is used by Outlook Web Access unless the user uses Regional Settings in Outlook Web Access to change the language and time zone. The default value for this setting is 0. This means the default client language is not defined. If the default client language is not defined, users will be prompted to choose a language and time zone the first time that they log on to Outlook Web Access. If the default client language value is defined, users will not be prompted to choose a language and the Outlook Web Access time zone will use the time zone of the Client Access server. Defining the default client language causes the default folders to be renamed based on the specified language. Users can change the client language and time zone by using Regional Settings in Outlook Web Access, and can rename the default folders after they log on.
  
• The client languages are set on individual mailboxes and affect the language that is used in Outlook and Outlook Web Access. If multiple languages are configured, the first language in the list that is supported by the Web browser will be used. If none of the languages in the default languages list is supported by the Web browser, the Client Access server language will be used.
  

To perform the following Exchange Management Shell procedure, the account you use must be delegated the Exchange Server Administrator role and membership in the local Administrators group for the target server.

For more information about permissions, delegating roles, and the rights that are required to administer Exchange 2007, see Permission Considerations.

Note:
For all Arabic, Hebrew, and Urdu text to display correctly in Outlook Web Access, support for languages that are read from right-to-left and for script languages must be installed on the client computer. Asian languages might also require that the East Asian language support be installed on the client computer.

The following table lists the languages and locales that can be configured in the Exchange Management Shell, and their associated codes.

Available languages and locales and their associated codes

 To use the Outlook Web Access client to configure language settings

1. Use a Web browser to access Outlook Web Access.

2. Click Options, and then click Regional Settings.

3. Under Language, in the Choose language list, click the language that you want to use.

   Note:
   The language that you select will determine the date and time settings in the Date and Time Formats section.

4. Click Save to save your language settings.

 To use the Exchange Management Shell to configure the logon and error language settings for Outlook Web Access

1. Run the following command to set the logon and error language setting:

   Set-OwaVirtualDirectory -identity "Owa (Default Web Site)" -LogonAndErrorLanguage <language code>

 To use the Exchange Management Shell to configure the default client language setting for an Outlook Web Access virtual directory

1. Run the following command to set the default client language setting:

   Set-OwaVirtualDirectory -identity "Owa (Default Web Site)" -DefaultClientLanguage <language code>

 To use the Exchange Management Shell to configure the client languages setting for an individual mailbox

1. Run the following command to set the client languages setting for an individual mailbox:

   Set-Mailbox -identity <mailbox identity> -languages <language code>

For more information about syntax and parameters, see Set-OwaVirtualDirectory and Set-Mailbox.