If you've spent any time looking at Exchange 2007, you've seen some pretty radical change—some very visible and some under the hood. A migration to Exchange 2007 will require admins to think about Exchange very differently, and will also require IT to figure out how to support some really useful new features.
One such feature, WebReady Document Viewing, is a more-than-welcome addition to Exchange Server. Implemented in Outlook Web Access (OWA), WebReady Document Viewing provides users with a way to safely view certain attachments from within OWA. In previous versions of OWA, a user was required to download most file attachments before opening them. With WebReady Document Viewing, supported attachments are first converted to HTML and then displayed in the OWA window itself. Even better, the native application need not be installed locally in order for the supported attachment to be viewed. This is a very good time-saving feature. WebReady Document Viewing supports the following file extensions:
Using Exchange 2007 management tools, you can also determine how users logging in to OWA should interact with documents. You can further refine this by changing the behavior depending on the type of computer from which the user is accessing OWA. For example, in extremely secure environments, you could decide that users logging in from a public computer are not allowed to view attachments at all. Or, for some users, you can force them to use the existing Exchange Server behavior, which dictates that users will download attachments.