When you use the Outlook Web Access client to open a compressed (.zip) file attachment that you downloaded from an Exchange Server 2003 computer, the file is corrupted

When you use the Microsoft Office Outlook Web Access client to open a compressed (.zip) file attachment that you downloaded from an Microsoft Exchange Server 2003 computer, the file is corrupted. You receive the following error message:

This problem may occur if the following conditions are true:

• Your Outlook Web Access front-end server has forms-based authentication enabled.
• Gzip data compression is enabled for Outlook Web Access.

When the content-encoding is "application/zip," the gzip filter compresses and may corrupt the attachment when the client downloads the e-mail message from the Outlook Web Access server.

Service pack information

To resolve this problem, obtain the latest service pack for Exchange Server 2003. For more information, click the following article number to view the article in the Microsoft Knowledge Base:

Hotfix information

A supported hotfix is available from Microsoft. However, this hotfix is intended to correct only the problem that is described in this article. Apply this hotfix only to systems that are experiencing this specific problem. This hotfix might receive additional testing. Therefore, if you are not severely affected by this problem, we recommend that you wait for the next software update that contains this hotfix.

If the hotfix is available for download, there is a "Hotfix download available" section at the top of this Knowledge Base article. If this section does not appear, contact Microsoft Customer Service and Support to obtain the hotfix.

Note If additional issues occur or if any troubleshooting is required, you might have to create a separate service request. The usual support costs will apply to additional support questions and issues that do not qualify for this specific hotfix. For a complete list of Microsoft Customer Service and Support telephone numbers or to create a separate service request, visit the following Microsoft Web site: Note The "Hotfix download available" form displays the languages for which the hotfix is available. If you do not see your language, it is because a hotfix is not available for that language.

Prerequisites

To install this hotfix, you must have Exchange Server 2003 Service Pack 1 (SP1) installed. For additional information about how to obtain Exchange Server 2003 Service Pack 1, click the following article number to view the article in the Microsoft Knowledge Base:

Restart requirement

You do not have to restart your computer to install this hotfix. However, the following Exchange and Microsoft Internet Information Services (IIS) services are automatically restarted when you install this hotfix:

• World Wide Web Publishing Service
• Simple Mail Transport Protocol (SMTP)
• Microsoft Exchange Routing Engine
• Microsoft Exchange POP3
• Microsoft Exchange IMAP4
• IIS Admin Service

Hotfix replacement information

This hotfix does not replace any other hotfixes.

File information

The English version of this hotfix has the file attributes (or later file attributes) that are listed in the following table. The dates and times for these files are listed in coordinated universal time (UTC). When you view the file information, it is converted to local time. To find the difference between UTC and local time, use the Time Zone tab in the Date and Time tool in Control Panel.

Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section. This problem was first corrected in Exchange Server 2003 Service Pack 2.

For additional information about how to enable gzip compression in Exchange Server 2003, click the following article number to view the article in the Microsoft Knowledge Base: For additional information about Microsoft software updates, click the following article number to view the article in the Microsoft Knowledge Base: