Microsoft first introduced Microsoft® Office Outlook® Web Access in Microsoft Exchange Server 5.0 so that clients could access their Exchange Server mailboxes through a Web browser. Microsoft has made significant improvements in Office Outlook Web Access in each new version of Exchange Server to provide support for a larger number of users, better performance, and improved functionality for clients. The latest version of Outlook Web Access in Microsoft Exchange Server 2007 provides most of the functionality of the Microsoft Office Outlook 2007 client.
This chapter explores Outlook Web Access to help you learn why it can be an important feature to implement and how to best put it to work for you, and also to help you put it to work as an alternative or complement to Microsoft Office Outlook 2007.
With Outlook Web Access and a Web browser, users can send and receive messages, view and modify their calendars, and perform most of the other tasks available through Office Outlook 2007. The features and appearance of Outlook Web Access depend on the version of Exchange Server that is hosting Outlook Web Access. Each successive version of Exchange Server adds a new look and new capabilities.
Outlook 2007 provides full access to an Exchange Server mailbox. Although Outlook Web Access isn’t intended as a replacement for Outlook 2007, it is useful for roaming users who want to access the most common mailbox features when they don’t have access to their personal Outlook 2007 installation. Linux, Unix, and Macintosh users can also benefit from Outlook Web Access by accessing Exchange Server mailboxes and participating in workgroup messaging and scheduling. In addition, Outlook Web Access can save the administrative overhead and support associated with deploying Outlook 2007 to users who don’t need everything that Outlook 2007 has to offer. These users can use a free Web browser to access many functions provided by Exchange Server. However, you must still purchase a client access license for each user or device that accesses the Exchange Server computer, even if the users do not use Outlook 2007 to connect to the server.
Because e-mail is the primary function of Exchange Server and Outlook 2007, Outlook Web Access supports e-mail access. Users can view message headers and read messages (see Figure 44-1) as well as send, reply to, forward, and delete messages. This last capability—deleting messages—might seem commonplace, but it is a useful feature. If your mailbox contains a very large attachment or a corrupted message that is preventing you from viewing your messages in Outlook 2007, you can use Outlook Web Access to delete the message without downloading or reading it. Just open your mailbox in your Web browser, select the message header, and delete the message.
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You can also use the Outlook 2007 remote mail feature to download only message headers, not message bodies. This capability is useful when you need to get your mail without downloading a message with a large attachment.
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For details on using remote mail with Exchange Server, see the section "Using Remote Mail" in Chapter 43. For details on using remote mail with other types of e-mail servers, see the section "Understanding Remote Mail Options" in Chapter 15.
Exchange 2000 Server and Exchange Server 2003 and 2007 offer additional features for messaging with Outlook Web Access. For example, Outlook Web Access in these versions of Exchange Server supports Hypertext Markup Language (HTML)–based messages as well as rich text messages. You also can access embedded objects in messages (another feature not supported by Exchange Server 5.x).
As mentioned earlier, you’re not limited to just messaging—you can also access your Calendar folder through Outlook Web Access. You can view and modify existing items and create appointments (see Figure 44-2). You can’t perform all the same scheduling tasks through Outlook Web Access that you can with Outlook 2007, but the ability to view your schedule and add appointments is useful, particularly when you’re working from a remote location or on a system without Outlook 2007 installed.
Contacts are another type of item you can manage through Outlook Web Access. You can view and modify existing contact items and add new ones (see Figure 44-3). Other features in Outlook Web Access in Exchange 2000 Server and later include support for ActiveX® objects, multimedia messages, and public folders containing contact and calendar items.
Exchange Server 2003 adds new features for Outlook Web Access that are not included in Exchange 2000 Server. For example, the Outlook Web Access interface more closely matches the Office Outlook 2003 interface, and Outlook Web Access also adds spell checking, access to task lists, Secure Multipurpose Internet Mail Extensions (S/MIME) support, and HTML content blocking. These features carry forward into Exchange Server 2007. Outlook Web Access in Exchange Server 2007 also offers some new features:
Schedule Out of Office messages and send to internal and/or external recipients
Use the Scheduling Assistant to efficiently book meetings
Access SharePoint® documents without a VPN or tunnel using LinkAccess
Use WebReady Document Viewing to read attachments in HTML even if the application that created the document is not installed locally
Access RSS subscriptions
View content in Managed E-Mail Folders
Retrieve voice mail or fax messages through Unified Messaging integration
Search the Global Address List (GAL)
Improved security and the capability for administrators to force HTML-only document viewing to prevent data from being left on public computers
Self-service support to enable users to request a Unified Messaging PIN reset, issue a remote wipe request to wipe a lost or stolen mobile device, and manage the safe and blocked senders lists
A light Outlook Web Access interface for use on slow connections
Support for quick searches
Capability to retrieve documents from a SharePoint link without requiring a VPN connection to the SharePoint site
Use HTML to translate and view a variety of document types, including Office documents and PDF documents, without having the native application installed on the client computer
Prelicensing of Information Rights Management (IRM)–protected content for faster client retrieval
For all its usefulness, Outlook Web Access has some limitations, but these limitations depend on the version of Exchange Server you use. For example, you can access your Tasks folder with Outlook Web Access in Exchange 2000 Server, but you can’t create tasks. With Outlook Web Access in Exchange Server 2003 and 2007, however, you can create tasks. Likewise, you can view the Journal folder with Outlook Web Access 2000, but you can’t add journal entries. With Outlook Web Access in Exchange Server 2003, you can view journal entries and post messages to the Journal folder, but you cannot create new journal items. Outlook Web Access with Exchange Server 2007 provides no access to the Journal.
You can’t use your mailbox offline through Outlook Web Access as you can through Outlook 2007 and an offline folder (OST) file. Unlike Outlook 2007, Outlook Web Access doesn’t support timed delivery and expiration for messages. However, Outlook Web Access provides a spell checker and includes the capability to define message rules for Outlook Web Access.
To access your mailbox through Outlook Web Access, you can use any Web browser that supports JavaScript and HTML version 3.2 or later, including Microsoft Internet Explorer® 4.0 or later and Netscape 4.0 or later. Some features, however, rely on Internet Explorer 5 or later, including drag-and-drop editing, shortcut menus, and native Kerberos authentication. In addition, browsers that support Dynamic HTML (DHTML) and Extensible Markup Language (XML) offer a richer set of features than those that do not. For example, Internet Explorer 5.x and later offer an interface for Outlook Web Access that is much closer to the native Outlook 2007 client, including a folder tree for navigating and managing folders as well as a Reading Pane.
Outlook Web Access in Exchange 2000 Server provides three options for authentication:
Basic Use clear text and simple challenge/response to authenticate access. This option offers the broadest client support but also offers the least security because passwords are transmitted as clear text.
Integrated Windows. Use the native Microsoft Windows authentication method for the client’s operating system. On systems running Microsoft Windows 2000, for example, Internet Explorer uses Kerberos to authenticate on the server. Other Windows platforms—including Microsoft Windows 9x, Microsoft Windows NT®, and Microsoft Windows Me—use NTLM challenge/response rather than Kerberos. Integrated Windows authentication provides better security than basic authentication because passwords are encrypted. The client doesn’t need to enter authentication credentials because the browser uses the client’s Windows logon credentials to authenticate on the Outlook Web Access server.
Anonymous. Use anonymous access for public folders in the Exchange Server store. This option can simplify administration.
Exchange Server 2003 and Exchange Server 2007 support some additional options because of additions in IIS 6.0:
Digest Authentication. This authentication method works only with Active Directory® accounts. It offers the benefit of sending passwords as a hash rather than in plain text. However, to use digest authentication, you must configure Active Directory to allow reversible encryption, which reduces security. See the Active Directory online documentation for Microsoft Windows 2000 Server and Microsoft Windows Server® 2003 for more detailed information on reversible encryption.
.NET Passport Authentication. This method enables users to authenticate with their Microsoft Passports.
In addition to these authentication methods, Outlook Web Access supports the use of Secure Sockets Layer (SSL) to provide additional security for remote connections.