The W3wp.exe process may crash on an Exchange 2007 CAS server after you use Entourage to send a message that is larger than 48 KB

Consider the following scenario:

• You try to send a message that is larger than 48 kilobytes (KB) by using Entourage.
• The message is sent through the Client Access server (CAS) role of Exchange Server 2007.
• Your mailbox is located on the mailbox server role of a Windows Server 2008-based computer that is running Exchange Server 2007.

In this scenario, the W3wp.exe process crashes on the CAS server. Additionally, the following event is logged in the Application log:

Log Name: Application
Source: Application Error
Event ID: 1000
Task Category: (100)
Level: Error
Keywords: Classic
Description: Faulting application w3wp.exe, version 7.0.6001.18000, time stamp 0x47919ed8, faulting module exprox.dll, version 8.1.240.5, time stamp 0x47427a9a, exception code 0xc0000005, fault offset 0x0000000000068511, process id 0x%9, application start time 0x%10.

To resolve this problem, download Update Rollup 5 for Exchange 2007 Service Pack 1. Then, install Update Rollup 5 on the Exchange server. To download Update Rollup 5 for Exchange 2007 Service Pack 1, visit the following Microsoft Web site: For more information about Update Rollup 5 for Exchange 2007 Service Pack 1, click the following article number to view the article in the Microsoft Knowledge Base:

Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.