Software

Build Your Skills: Exchange 2000 Outlook Web Access is much improved

Know the back-end changes that provide advancements to OWA.


When examining the benefits that Exchange 2000 provides, one of the items demanding consideration is Outlook Web Access (OWA). Exchange 2000 represents an almost complete redesign of OWA, with the result being more user friendly and functional than ever. In previous versions of Exchange Server, OWA was an add-on product. With Exchange 2000, OWA becomes an integral part of the Exchange Server Platform. This integration and other back-end changes provide advancements in three key areas: security, scalability, and usability.

Security
OWA 2000’s logoff procedure illustrates one of the greatest advances in security. In previous versions, cookies were placed on a user’s machine to validate the user’s session. When the user wanted to log off and clicked the logoff button, the cookie would be invalidated. However, if the user simply closed his or her browser without logging off, the cookie would remain valid, enabling another person to reopen the browser and gain access to the user’s mailbox. OWA 2000 does not use cookies; so when the user closes all open browser windows, he or she is logged off.

Scalability
In the past, OWA came under heavy fire from companies that deployed it to a large number of users. No matter how robust the server used for OWA was, it would show significant performance degradations around 500 users and “max out” at about 700-800 users. Microsoft greatly increased OWA’s scalability in Exchange 2000. The key to this increase is Microsoft’s removal of its Messaging Application Program Interface (MAPI) and remote procedure calls (RPCs), which were used to carry data between the IIS application and Exchange. Browsers now channel all communications through an IIS 5.0 application that connects directly to the Information Store. System Administrators still need to measure several vital counters, however, to ensure that performance levels are maintained as users increase. This can be accomplished by using the Performance Logs and Alerts snap-in in Windows 2000.

Usability
The redesign of Exchange provided perhaps the most visible changes in usability. OWA now more closely resembles Microsoft Outlook 2000/2002. Gone are the Active Server Pages (ASP) and Collaboration Data Objects (CDO) code. OWA 2000, when used with Internet Explorer 5.0 or greater, now provides support for Dynamic HTML (DHTML), Extensible Markup Language (XML), and Extensible Stylesheet Language (XSL). Also included is WWW Distributed Authoring and Versioning (WebDAV), which lets browsers execute document-management functions on server data.

Unsupported features
Despite these advancements, there are still a number of features not available in OWA 2000. These include:
  • No support for tasks, journaling, or notes.
  • No support for working offline.
  • No support for S/MIME messages or digital signatures.
  • No spell checker.
  • No automatic deletion of deleted items.
  • No message flags or Inbox rules. Server side rules will still fire, but they cannot be accessed from the OWA client.
  • No searching for messages.
  • No WordMail or other Office integration.

Supported features
Now that you know what OWA 2000 does not support, here is a list of some of the new features it does support, as well as some visual examples of the advancements that have taken place:
  • Contact folders have an improved look and feel (see Figure A).

  • Figure A

    • Friendly URLs to access items in folders. For example, the following URL, http://servername/exchange/patricia/inbox/messaging%20options.eml, would reference an item with the subject “Messaging Options” (the %20 replaces the space) in my mailbox (patricia) on my Exchange server (servername).
    • Attachments can now be included in messages posted to public folders.
    • Calendar View, shown in Figure B, now displays week numbers (Exchange 2000 Service Pack 1).

    Figure B

    • Additional support for foreign character sets (Exchange 2000 Service Pack 1).
    • Support for embedded items and ActiveX objects.
    • Multimedia content: OWA 2000 allows for an audio or video clip to be embedded directly into a message.
    • Deleted item recovery, shown in Figure C (with Exchange 2000 Service Pack 1).

    Figure C

    • Keystrokes such as [Ctrl]K (Check Names) are supported.
    • Columns can be sorted. Simply click on a column heading to sort items by that column.
    • Grouped views are now supported (see Figure D).

    Figure D

  • Public folders containing contact and calendar items are supported. Contacts and Calendar items in Public Folders now display just like they would in the standard Contact or Calendar folder.

  • Conclusion
    Microsoft Exchange 2000’s OWA is just one of many enhancements that should factor into any upgrade decision. While OWA 2000 is not a complete replacement for Microsoft Outlook 2000 or 2002, it may very well become the client of choice for mobile users of Exchange Server.

    Patricia Cardoza is an Outlook Developer and Microsoft Outlook MVP. She has been developing with Outlook since Outlook 97 and specializes in workflow and collaborative solutions. She is an MCP in Exchange and Outlook Collaborative Solutions and is currently diving into the exciting world of Exchange 2000 Development. She can be reached at patricia@cardozasolutions.com.


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