To modify RPC over HTTP Exchange Desktop policy settings

1. In the left pane of the Administration Console, expand the Policies container until Exchange Desktop policies are visible.

2. In the right-hand pane, double-click the name of the policy you want to edit.

   The policy's properties are displayed.

3. Click the Advanced tab.

4. Next to List settings from, select Outlook.

5. Edit the following settings as required.

   Double-click a setting to edit it, or click it once to select it and then click Modify.

   • RPC over HTTP restrictions. By default Outlook RPC over HTTP client access is disabled (Disable User Extensions). Configure the functionality that is required in Outlook by selecting one of the other values:

     None	All Enterprise Vault client functionality is available.
     Disable User Extensions	Enterprise Vault functionality is not available in Outlook RPC over HTTP clients. This is the default value.
     Disable Vault Cache only	Vault Cache is disabled.
     Disable PST Import only	Client-side PST migration is disabled. Note that currently you cannot use client-side PST migration to migrate any files that reside on mapped network drives when using an Outlook client in RPC over HTTP mode.
     Disable Vault Cache and PST Import	Vault Cache and client-side PST migration are disabled.

   • RPC over HTTP connection. This setting controls how the Enterprise Vault Outlook Add-Ins connect to the Enterprise Vault server that hosts the archive. The value for this setting can be Use proxy or Direct. The options have the following effect.

     • In an Exchange Server 2003 environment. With the default value, Use proxy, the client routes all Enterprise Vault requests to the Enterprise Vault server using the Exchange RPC proxy server.

       If the value is Direct, then the client attempts to connect directly to the default Enterprise Vault server.

       When the user requests an Enterprise Vault operation, then the client first attempts to contact the default Enterprise Vault server. If the connection cannot be made, and RPC over HTTP connection is set to Use proxy, then the URL configured for RPC over HTTP Proxy URL is used.

     • In an Exchange Server 2007 environment. With the default value, Use proxy, the client routes all Enterprise Vault requests to the Enterprise Vault server using the Enterprise Vault proxy server. The URL for the proxy server must be specified in the RPC over HTTP Proxy URL setting.

       When the user requests an Enterprise Vault operation, then the client first attempts to contact the default Enterprise Vault server. If the connection cannot be made, and RPC over HTTP connection is set to Use proxy, then the URL configured for RPC over HTTP Proxy URL is used.

       If the value is Direct, then the client attempts to connect directly to the default Enterprise Vault server.

     The value can be set to Direct even if you have an ISA Server configured. In this situation you must publish on the ISA Server the URLs of all the Enterprise Vault servers that host the archives.

   • RPC over HTTP Proxy URL. This setting enables you to specify an alternative URL for the Enterprise Vault server. Enterprise Vault Outlook Add-Ins use the URL when Outlook is configured to use RPC over HTTP, and RPC over HTTP connection is set to Use proxy.

     • In an Exchange Server 2003 environment. By default, clients connect to the virtual directory, EnterpriseVaultProxy, on the Exchange RPC proxy server.

     • In an Exchange Server 2007 environment. If RPC over HTTP connection is set to Use proxy, the clients connect to the URL specified in this setting.

     If you change the name of the virtual directory, then you can use this setting to specify the alternative URL. For example, if you change the virtual directory name to EVProxy, then you use the RPC over HTTP Proxy URL setting to specify the URL:

     HTTP://Web_server/EVProxy
     

6. The settings are applied to mailboxes during the next synchronization run of the Exchange Mailbox task. If you want to apply the changes before the next synchronization, run Synchronize, which is on the Synchronization tab of the Exchange Mailbox task's properties.