Use Exchange Server 2003 Outlook Web Access Basic with Browsers Earlier Than Internet Explorer 5.01

Outlook Web Access in Exchange Server 2003 is a full-featured e-mail client, with support for rules, spelling checker, signed and encrypted e-mail, and many other improvements. The interface is also redesigned to provide an enhanced user experience that is similar to the experience that is provided by Outlook 2003. New features include a Reading Pane (previously named the Preview Pane in Outlook) and an improved Navigation Pane.

Outlook Web Access Versions

Exchange 2003 now includes two versions of Outlook Web Access:

• Outlook Web Access Premium is designed for Microsoft Internet Explorer 5.01 or later. Outlook Web Access Premium includes all Outlook Web Access features, including the new enhanced features for Exchange 2003. Microsoft Internet Explorer 6.0 is required for some features.
• Outlook Web Access Basic is designed to work in browsers that support the HTML 3.2 and the European Computer Manufacturers Association (ECMA) script standards. It provides a subset of the features that are available in Outlook Web Access Premium.

If you are running Windows Internet Explorer 5.01 or later, and you have Forms Based Authentication turned on, the logon page permits you to choose Outlook Web Access Premium or Basic. The Premium version is the default selection.

If you have a slow network connection and you want to check your Inbox or search for an appointment, the Outlook Web Access Basic client may be a better option. However, Outlook Web Access Basic does lack useful features that available in the Outlook Web Access Premium.

Outlook Web Access Basic supports any browser that is fully compliant with the HTML 3.2 and European Computer Manufacturers Association (ECMA) script standards. However, because some browsers are not fully compliant with these standards, Microsoft recommends that you use Internet Explorer 5.01 or later, or Netscape Navigator 4.7 or later. These browsers have been tested with Outlook Web Access.

Microsoft Outlook Web Access (OWA) for Exchange Server 2003 works best when you use Microsoft Internet Explorer 5.01 or later to gain access to OWA, because Internet Explorer 5.01 uses dynamic HTML (DHTML) in combination with XML to provide extensive capabilities for collaborative applications. Supported Web browsers that are earlier than Internet Explorer 5.01 (Microsoft Internet Explorer 4.0 or Netscape Navigator 4.0 to 4.6) do not fully use OWA for Exchange Server 2003 capabilities, because these browsers do not support DHTML and XML.

You can only use Kerberos authentication with Internet Explorer 5.01 for Windows 2000 and later.

Although other supported browsers do not offer the complete functionality that Internet Explorer 5.01 or later does with OWA for Exchange Server 2003, these earlier supported browsers still support OWA for Exchange Server 2003 to match Microsoft Outlook more closely than earlier versions of OWA. Even though earlier supported browsers minimize the use of client-side scripting, earlier supported browsers operate in a two-frame mode with OWA for Exchange Server 2003, with a navigation panel on the left that remains constant. Only the right pane renders pages, a feature that reduces network traffic. The third-party products that are discussed in this article are manufactured by companies that are independent of Microsoft. Microsoft makes no warranty, implied or otherwise, regarding the performance or reliability of these products.