After the 1999 Microsoft Exchange Conference (MEC), I wrote in "Exchange 2000 for Developers and Users," January 2000, that even though Exchange 2000 Server supported many new development strategies, something was missing. The new version didn't offer techniques to enable disconnected or occasionally offline users to take advantage of the new Exchange 2000 features. A year later, I'm happy to report that Microsoft plans to deliver those missing pieces in the next version of Microsoft Outlook in late spring 2001.
At the Microsoft Exchange and Collaborative Solutions Conference 2000 in Dallas in October, Microsoft demonstrated Outlook 10 (the product's current code name), along with a new Microsoft Office family product called Office Designer. Both products will play a huge role in establishing Exchange 2000 as an applications platform, reaching beyond inhouse Outlook clients to support non-Outlook users through browser access and offline Outlook clients.
Outlook 10's Local Web Storage System
At the heart of Outlook 10 is the biggest architectural change in the product since Outlook 97's release—the Local Web Storage System (LWSS). The LWSS uses the same code as Exchange 2000's Web Storage System—but scaled to run on a client system. The LWSS functions not only as a local cache of information from the server but also as a full applications platform, including a local Active Server Pages (ASP) engine. The cache includes both data and all the components needed to run a Web Storage System application, enabling a mobile user to take, for example, an entire sales force automation application on the road.
The files that the LWSS uses have an .lis extension. Think of the LWSS as a replacement for both the Personal Folders (.pst) and Offline Folders (.ost) files that earlier versions of Outlook relied on. You can still use Outlook 10 to access data in these types of information stores, but Outlook 10 also creates a Local Information Store (LIS) automatically for use as a cache of Exchange 2000 mailbox data. Users can also create .lis files similar to the way they might have used secondary .pst files in earlier versions, but these .lis files aren't subject to the 2GB size limit of .pst files.
As a cache, the LWSS is similar to the memory cache that a hard disk uses or the file cache that Microsoft Internet Explorer (IE) uses for recently downloaded files. When you're working online and switch to a new folder, Outlook downloads only the headers of items in the first screen into the cache. As you open each item, Outlook saves that item to the cache. In the background, Outlook is also downloading the additional headers for items in that folder.
The first time you open an item in Outlook, the LWSS must retrieve it from the server and store it in the cache. The next time you open that item, Outlook looks first in the cache. If it finds the item, Outlook displays the item immediately without going back to the server. At the same time, though, if you're working online, the LWSS asynchronously contacts the server to confirm that the data is up-to-date. If the data has changed on the server since Outlook stored the item in the cache, the LWSS retrieves the updated item, stores it in the cache, and displays it.
The LWSS performs much of its work asynchronously in the background as you handle Outlook tasks. You also have much more control over how much of each item Outlook downloads—the header only, the header and body of the item, or the complete item including attachments. Because of this architecture, Outlook 10 won't hang or appear to hang when you open an item from an Exchange 2000 folder. For example, if you're working online and you open a long message, Outlook displays a progress dialog box with a Cancel button you can use to stop the downloading of that item. Another example is if you're working offline and try to open an item that you haven't opened previously, you'll see a message asking whether you want to mark the item for downloading the next time Outlook connects to the server.
To a great extent, the LWSS eliminates the distinction between working offline and working online. In one of the most effective demonstrations at MEC, the presenter pulled out a pair of scissors and cut the network cable while Outlook 10 was running. Outlook didn't hang or present a message that it couldn't connect with the server. The presenter was able to continue working with the data already in the LWSS cache without the need to shut down and restart Outlook in offline mode.
Another advantage of the LWSS is that when Outlook 10 communicates with Exchange 2000 through the LWSS, Outlook 10 uses the HTTP protocol, not remote procedure calls (RPCs) as in earlier versions. This process will make it easier for companies to give remote users access to their mail over the Internet through corporate firewalls. Microsoft recommends a front-end/back-end topology as a solution for offsite access and provides a white paper on the topic (http://www.microsoft.com/exchange/techinfo/e2kfrontback.htm). Data transfer between the LWSS and the Exchange 2000 server automatically uses gzip, an Internet compression algorithm.
Outlook 10 Send/Receive Improvements
As Microsoft did in Outlook 2000 and Outlook 98, the company has targeted many of the biggest improvements in Outlook 10 at disconnected users—users who always work from outside the corporate network, who work occasionally from home, or who travel in their jobs. In addition to changing the nature of the local data file, Microsoft has completely rewritten the synchronization engine. You can set up Outlook 10 to synchronize with an Exchange 2000 mailbox continuously in the background. You can also set up specific folders to synchronize on demand or on a particular schedule. Outlook 10 provides dialog boxes for setting up send/receive groups that handle the data transfer for different combinations of folders. You might use different send/receive groups when you work in the office, work from home on a broadband connection, or work from a hotel over a dial-up connection.
Figure 1 shows how you set up Outlook 10 to send and receive items from a user's mailbox. Notice that the Inbox is set to receive only description and contents (i.e., headers and body)—not attachments—for new items. Another way to limit the amount of information initially downloaded is to filter a folder, as Figure 2 shows.
Outlook 10 as an Applications Platform
Aside from its offline implications, the LWSS offers some key advantages as an applications platform, particularly to support disconnected users. Not only does the LWSS cache data for offline use, but it also caches the resources needed to run applications built on the Exchange 2000 Web Storage System. The LWSS automatically caches in the LIS all the ASP and other files needed to run the application. Therefore, if the user has been using the application, then unplugs from the network and leaves for a trip, all the components needed to run the application travel with the user automatically. The user can create new items while working offline and synchronize them back to the server when it's convenient.
Introducing Office Designer
Another application making its debut at MEC 2000 was the Office Designer, which will be part of the Microsoft Office 10 package. Designer is a visual development tool for building collaborative solutions for Exchange 2000's Web Storage System, for the document management and collaboration server code-named Tahoe (which Microsoft also introduced at MEC 2000), and for Outlook 10's LWSS. Designer is an extension of the rapid-deployment technique first presented in the Team Folders add-on for Outlook 2000. To simplify creating folder-based applications, Microsoft plans to ship Designer with eight templates:
- Project (which combines all the other templates)
- Digital Dashboard
- Issue Tracking
- Document Library
- Simple List
All the templates share a style sheet for a consistent look, and they have forms and code that let you maintain a user list, set access rights, and handle other settings.
Instead of using templates, you can create new Web Storage System applications from scratch. You can even build applications while working offline, then synchronize the applications back to the server. This feature will be great for developers because they won't need to carry a server with them to demonstrate an application to customers.
Figure 3 shows how different Office Designer's Integrated Development Environment (IDE) is from the Notepad-like code window that Outlook developers have used since Outlook 97. Separate windows within the IDE show all ASP pages, views, item types, and other resources associated with the application. These resources can include
- A toolbox, including simple actions for the most commonly used application tasks, such as opening and saving an item
- Each ASP page displayed in both what you see is what you get (WYSIWYG) layout and HTML views (Figure 3 shows a form to display issues from the Issue Tracking templates)
- Fields associated with a specific type of item
Built on the Visual Studio.NET shell (the next version of Microsoft Visual Studio—VS), the Designer IDE includes many of the syntax-checking, color-coding, and other features that users of VS and Visual Basic for Applications (VBA) have come to depend on and that were never available in Outlook form design. For developers coming from an ASP environment, Microsoft contends that the built-in data binding, simple actions, and other Designer features can eliminate as much as one-third of the code needed to produce the same application with ASP alone.
The Future of Outlook
Microsoft demonstrated a host of other new features for Outlook 10 at MEC 2000, many of them from the wish list that users and administrators have been building up for several years. This wish list includes
- On-the-fly color-coding for calendar items
- An end to the distinction between Internet Mail Only (IMO) and Corporate Workgroup (C W) operating modes, with support for all kinds of mail accounts, including Exchange, Hotmail, IMAP and POP3 accounts, all in one mail profile
- A new feature to make it easy to propose an alternate time for a meeting
- A group schedule that looks like the existing meeting planner but with a time-line view showing each person's appointments
- One window for managing all reminders
- Buttons for accepting or rejecting meeting and task requests at the top of the preview pane
- A list of most-recently used mail recipients to make resolving the email addresses faster
However, despite the advances in the LWSS and these other new features, a future of Exchange Server without Outlook on the desktop seems more feasible than ever before. In his Windows 2000 Magazine article "Web-Enabling Exchange 2000" (February 2000), Tony Redmond wrote about the improved Outlook Web Access (OWA) in Exchange 2000 offering a stateless client—one that requires no installation or configuration on the desktop, because it relies on the user's browser.
Here's the future I see: The average user in a company works with OWA for mail, contacts, and calendar—maybe even tasks in some future version of Exchange—and then relies on Web Storage System applications built with Office Designer running in a browser for the type of public folder-based applications you commonly see in Outlook today. Users who choose to deploy Outlook 10 might include only disconnected users, power users who need some of the new features, and inhouse developers who need Outlook 10 in order to work with Office Designer.
Corrections to this Article:
- Since this article was written, Microsoft has removed the Office Designer program and the Local Web Storage System (LWSS) from its Office 10 release. Microsoft's announcement said that the company is "currently evaluating the future direction for the functionality provided in these features."