One of the biggest feature requests we had in Exchange 2003 OWA was a way to let users view attachments without having to save them to disk or open them in a locally-installed application.  In Exchange 2007 OWA, we are introducing WebReady Document Viewing, which lets users do just that.  WebReady Document Viewing allows users to view certain attachments as a web page.  Exchange 2007 does the conversion, so the user doesn't need anything other than a web browser.  Currently, we support Word (.doc), Excel (.xls), PowerPoint (.ppt), and PDF (.pdf) documents.  This is a big win for corporations and users.  Corporations don't need to worry about their IP being left in caches on public machines, like airport kiosks.  Users don't need to download the attachment and then fire up an application to view it.  They can just click on the "View as Web Page" link and the WebReady Viewing version will open.

Of course, having a different way to get to attachments makes creating an attachments policy a little trickier.  I'll explain how administration of attachments and Webready Document Viewing works in OWA2007 in this blog post.

The most important thing to understand is that WebReady Document Viewing is a method of accessing attachments.  This means that you need to decide how to grant access to attachments.  It is perfectly valid to prevent users from opening or saving attachments, but still allow them to see the WebReady version of the supported types.

The following screenshots show the OWA properties page (Server Configuration/Client Access/Outlook Web Access/owa (Default Web Site)) in the Exchange Management Console. I'll explain each option along with the corresponding Exchange Management Shell properties.

• DirectFileAccessOn{Public,Private}ComputersEnabled: enables/disables access to attachments via a locally (client-side) installed viewer (e.g., Word)

• WebReadyDocumentViewingOn{Public,Private}ComputersEnabled: enables/disables WebReady Document Viewing

• ForceWebReadyDocumentViewingOn{Public,Private}First: forces users to see the WebReady Document Viewing version of the attachment before being allowed to save it to disk or open it in a locally-installed application. 

Here's how they work:

When OWA shows the user that there is an attachment with the message, it checks two sets of properties: the login mode (public or private) and the attachments and WebReady Document Viewing settings that apply to that login method.  DirectFileAccessOn{Public,Private}ComputersEnabled and WebReadyDocumentViewingOn{Public,Private}Computers are independent properties. Also note that users can only select public vs. private logons if using forms-based authentication. If using any other type of authentication, the logon mode is always private.

If DirectFileAccess is enabled for the current login method, the attachment will be available for downloading and viewing in an application running on the user's computer.  If it is disabled, the attachment cannot be downloaded or saved.

If WebReadyDocumentViewingOn is enabled for the current login method and the attachment is one of the supported types (Word 2003, Excel 2003, PowerPoint 2003, or PDF), OWA displays an "Open as Web Page" link next to it.

If ForceWebReadyDocumentViewingOn{Public,Private}First is enabled, the user's only option from the OWA message view will be to view the WebReady version. 

If DirectFileAccess is enabled, the WebReady Viewing page will give the user the option of saving or opening the attachment in a local application.  Otherwise, the user will only be able to view the attachment as a web page.

In next post, I will go over how to customize the settings for attachments.

- Rahul Dhar