XCCC: Exchange 2000 Server SP2 Server-Side OWA Registry Keys

This article is a summary of the server-side Microsoft Outlook Web Access (OWA) administrative registry modifications available with Microsoft Exchange 2000 Server Service Pack 2 (SP2). Some of these options have been available before the release of Exchange 2000 Server SP2. Other articles and the Exchange 2000 Help file (exadmin.chm) are referenced instead of documenting the features completely in this article.

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The following registry keys are set on the server and do not exist by default. They are all located (unless noted otherwise) in the following registry subtree: For most of these changes to take effect, you must restart the Information Store service.

DisablePassword
Some organizations may want to turn off this feature so that users can only change their passwords while inside the firewalls. When DisablePassword is set to 1, the Change Password button on the OWA Options page is hidden, so that users cannot change their password with OWA. For additional information, click the article number below to view the article in the Microsoft Knowledge Base: UserContextTimeout
UserContextTimeout is the value in minutes of user context timeout due to inactivity. User contexts take up resources on the server, so timing them out will allow the server to free up resources if the client is not using them. This is not an authentication timeout. The client's browser will still have a cache of the credentials. If the server times out the user context and the client then performs an action in OWA, the authentication information is sent back up to the server without user interaction and the server creates a new user context. For additional information, click the article number below to view the article in the Microsoft Knowledge Base: DisableMultimedia
Outlook Web Access users can download the Exchange Multimedia Control from the Options page. This control enables users of Microsoft Internet Explorer 5 or later to insert audio and video content into messages. Because of the size of multimedia messages, some administrators may want to prevent Outlook Web Access users from taxing Exchange Server resources by sending audio and video content over a wide area network (WAN). For additional information, click the article number below to view the article in the Microsoft Knowledge Base: UseRegionalCharset
When Outlook Web Access users use Internet Explorer 5 or later to send a message, recipients who have mail clients that are not Unicode Translation Format-8 (UTF-8) aware cannot view the message. A solution to this problem is to disable regional characters. In a FrontEnd/BackEnd configuration this change need to be done on both frontend and backend servers. For additional information, click the article number below to view the article in the Microsoft Knowledge Base: UseAltRegionalCharset
If the UseAltRegionalCharset key is not set or it is set to 0, uplevel browsers send messages in UTF-8 and downlevel browsers send messages in the appropriate encoding for the browser's acceptance language. For the following languages, downlevel browsers use the following encodings: If this key is set to 1, both uplevel and downlevel browsers send messages in the following encodings: This key only changes the behavior for browsers configured for the above languages. If both the UseRegionalCharset registry key specified noted above and this UseAltRegionalCharset registry key are both set, the UseAltRegionalCharset registry key will take precedence. For additional information, click the article number below to view the article in the Microsoft Knowledge Base: UseISO8859-1
Add the UseISO8859-1 key to use ISO 8859-1 for messages sent with OWA. In Exchange 2000 Server, messages with extended characters are encoded with UTF-8 by default. Because some clients on the Internet do not understand this encoding, a feature has been added to instead use a regional character set. For additional information, click the article number below to view the article in the Microsoft Knowledge Base: ResolveForeignUsers
Users in a different Windows 2000 Active Directory forest can read and post messages in your Exchange Server organization's public folders, if this external forest is trusted by your own. However, the names of these external users may not be resolved, which results in blank "From" fields. Local users can reply to the postings of these unresolved users, but no one can send mail directly to unresolved external users. Set this value to 1 so that posts to public folders from trusted AD forests will have a valid name in the From field.

For additional information, click the article number below to view the article in the Microsoft Knowledge Base: EnableLogoffWarning
If EnableLogoffWarning is set to 1, an alert message will appear each time the user tries to navigate away from Web client. If the key does not exist (default) or is set to 0, the alert will not appear. You must implement this key on each frontend and backend server for the warning to appear. Restart the W3SVC after you change this key. ReminderPollingInterval
This is the default minimum reminder polling interval in minutes. The default is 15 minutes, but administrators can customize this on a per-server basis. See the Exchange 2000 Server SP2 Help file for more information. ForceClientsDownLevel
This forces "downlevel" behavior in Internet Explorer 5.01 and later. Some proxy servers or firewalls strip out anything they do not understand, such as HTTP-DAV verbs that are used by newer browsers. Unexpected behavior can be exhibited by OWA if these verbs are stripped. One workaround is to use Secure Sockets layer (SSL); then the proxy or firewall cannot see these verbs. If this registry key is implemented, Internet Explorer 5.01 and later browsers will not exhibit the Internet Explorer 5 features.

For additional information, click the article number below to view the article in the Microsoft Knowledge Base: NewMailNotificationInterval
This setting is not user-customizable. The default New Mail Notification polling interval is 2 minutes if this registry key does not exist. If it does exist, the interval specified in this registry key will be used. Outlook Web Access users who use Internet Explorer 5 or later can receive a notification message at regular intervals when they receive new e-mail. See the Exchange 2000 Server SP2 Help file for more information about this registry value. Segmentation, also known as Tiered Licensing or Provisioning
Segmentation refers to the ability to selectively enable features of OWA. For example, calendaring, contacts, public folders, calendar reminders, new mail notification, and Internet Explorer 5 support can be disabled or enabled according to service offering. The ability to segment OWA available to administrators after the installation of Exchange 2000 Server SP2. OWA can be segmented on a per-server or a per-user basis. Per-user settings override per-server settings if both are in place.

MinimumFilterLevel (DWORD)
Allows administrators to decide whether users get unfiltered message bodies when going to the View As Web Page link. By default, dangerous content is always filtered, even if "&security=X" is not appended to the URL.

For additional information, click the article number below to view the article in the Microsoft Knowledge Base: