Q186788: XWEB: Cannot View Attachments in OWA on IIS 4.0 Computer

Article: Q186788
Product(s): Microsoft Exchange
Version(s): WINDOWS:5.5; WINNT:4.0
Operating System(s): 
Keyword(s): 
Last Modified: 22-JUN-2001

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The information in this article applies to:

- Microsoft Outlook Web Access, version 5.5 
- Microsoft Internet Information Server 4.0 
- Microsoft Exchange Server, version 5.5 
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SYMPTOMS
========

If you use Microsoft Outlook Web Access to view a message that contains an
attachment on a Microsoft Exchange Server computer that is running Microsoft
Internet Information Server (IIS) 4.0, you may be unable to open the attachment.
Microsoft Internet Explorer is able to display the contents of the attachment,
but other Internet browsers may not be able to do so.


CAUSE
=====

When you view a message that contains an attachment, Outlook Web Access uses the
IIS Multipurpose Internet Mail Extensions (MIME) table to determine which MIME
type is associated with the file's extension. This allows your Internet browser
to display the contents of the attachment.

In IIS 3.0, the MIME table is located in the registry. The MIME table is also
located in the registry in IIS 4.0, but it is located under a different registry
key. This prevents Outlook Web Access from determining which MIME type is
associated with a given extension. Because it cannot obtain the correct MIME
type, Outlook Web Access assumes that the MIME type is
"application/octet-stream." Some Internet browsers can display the contents of
the attachment under these circumstances, but others cannot.

WORKAROUND
==========

To work around this problem, use one of the following methods:

- Save the attachment to your hard disk, and then open the file from your hard
  disk.

- If the file type associated with the attachment exists, modify the file type
  so that the appropriate MIME type is associated with it. To do so, follow
  these steps:

  a. In My Computer or Windows NT Explorer, click Folder Options on the View
     menu, and then click the File Types tab.

  b. Click the appropriate file type in the list of registered file types, and
     then click Edit.

  c. Verify that the appropriate MIME type is selected in the Content Type
     (MIME) box, click OK, and then click OK again.

- If the file type associated with the attachment does not exist, create it. To
  do so, follow these steps:

  a. In My Computer or Windows NT Explorer, click Folder Options on the View
     menu, and then click the File Types tab.

  b. Click New Type.

  c. Type a description for the file type in the Description Of Type box, type
     the file's extension is the Associated Extension box, and then select the
     appropriate MIME type in the Content Type (MIME) box.

  d. Click New, type "open" (without quotation marks) in the Action box, type
     the full path and file name of the program used to open the file in the
     Application Used To Perform Action box, click OK, click OK again, and then
     click OK again. Note that you can click Browse to locate the program
     instead of typing the full path and file name manually.

MORE INFORMATION
================

In IIS 3.0, the MIME table is located under the following registry key:

  HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\Inetinfo
  \Parameters\MIMEMap

NOTE: The above registry key is one path; it has been wrapped for readability.

IIS 4.0 uses the MIME table located under the following registry key:

  HKEY_CLASSES_ROOT\MIME\Database\Content Type

STATUS
======

Microsoft has confirmed this to be a problem in Microsoft Outlook Web Access
version 5.5. This problem has been corrected in the latest U.S. Service Pack for
Microsoft Exchange Server version 5.5. For information on obtaining the Service
Pack, query on the following word in the Microsoft Knowledge Base (without the
spaces):

  S E R V P A C K


Additional query words: owa iis k2

======================================================================
Keywords          :  
Technology        : kbOutlookSearch kbiisSearch kbiis400 kbOWASearch kbOWA550
Version           : WINDOWS:5.5; WINNT:4.0
Issue type        : kbbug
Solution Type     : kbfix

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