Outlook Mobile Access users cannot access their mailboxes on a heavily-loaded Exchange Server 2003 computer

On a heavily-loaded Microsoft Exchange Server 2003 computer, users in your organization may not be able to access their mailboxes by using Microsoft Outlook Mobile Access. In this scenario, an Outlook Mobile Access user may receive an error message that is similar to the following:Additionally, all the following events may appear in the Application log on the Exchange Server 2003 computer:

Event 1

Event Type: Error
Event Source: MSExchangeOMA
Event Category: (1000)
Event ID: 1507
Date: date
Time: time
User: N/A
Computer: servername
Description: An unknown error occurred while processing the current request: Exception of type Microsoft.Exchange.OMA.DataProviderInterface.ProviderException was thrown.

Stack trace:
at Microsoft.Exchange.OMA.UserInterface.Global.Session_Start(Object sender, EventArgs e)
at System.Web.SessionState.SessionStateModule.CompleteAcquireState()
at System.Web.SessionState.SessionStateModule.BeginAcquireState(Object source, EventArgs e, AsyncCallback cb, Object extraData)
at System.Web.AsyncEventExecutionStep.System.Web.HttpApplication+IExecutionStep.Execute()
at System.Web.HttpApplication.ExecuteStep(IExecutionStep step, Boolean& completedSynchronously)
Inner Error: Exception has been thrown by the target of an invocation

Stack trace:
at System.Reflection.RuntimeConstructorInfo.InternalInvoke(BindingFlags invokeAttr, Binder binder, Object[] parameters, CultureInfo culture, Boolean isBinderDefault)
at System.Reflection.RuntimeConstructorInfo.Invoke(BindingFlags invokeAttr, Binder binder, Object[] parameters, CultureInfo culture)
at System.RuntimeType.CreateInstanceImpl(BindingFlags bindingAttr, Binder binder, Object[] args, CultureInfo culture, Object[] activationAttributes)
at System.Activator.CreateInstance(Type type, BindingFlags bindingAttr, Binder binder, Object[] args, CultureInfo culture, Object[] activationAttributes)
at Microsoft.Exchange.OMA.UserInterface.Global.Session_Start(Object sender, EventArgs e)
Inner Error: Exception of type System.OutOfMemoryException was thrown.

Event 2

Event Type: Error
Event Source: MSExchangeOMA
Event Category: (1000)
Event ID: 1503
Date: date
Time: time
User: N/A
Computer: servername
Description: An unknown error occurred while processing the current request: Exception of type System.OutOfMemoryException was thrown.

Event 3

Event Type: Error
Event Source: MSExchangeOMA
Event Category: (1000)
Event ID: 1503
Date: date
Time: time
User: N/A
Computer: servername
Description: An unknown error occurred while processing the current request: Exception of type System.OutOfMemoryException was thrown.

This problem may occur if Exchange Server 2003 is running on a Microsoft Windows 2000-based computer. In this scenario, virtual memory fragmentation may occur if Exchange Server 2003 is under a heavy load. You may experience this problem during stress-testing of your Exchange Server environment.

To resolve this problem, follow these steps.

Important This section, method, or task contains steps that tell you how to modify the registry. However, serious problems might occur if you modify the registry incorrectly. Therefore, make sure that you follow these steps carefully. For added protection, back up the registry before you modify it. Then, you can restore the registry if a problem occurs. For more information about how to back up and restore the registry, click the following article number to view the article in the Microsoft Knowledge Base:

1. Obtain and install the hotfix that is described in the following Microsoft Knowledge Base article:
   820745  (http://support.microsoft.com/kb/820745/ ) Failfast occurs when you experience an "out of memory" condition
2. Configure the following registry entry with a value of 1:
   HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\.NETFramework
   
   Value name: GCFailFastOnOOM
   Value type: REG_DWORD
   Value data: 1

After you configure this registry entry, if you experience an out-of-memory condition on your Exchange Server computer, an event that contains the following description is logged:

Failed to allocate numberOfbytes bytes with numberOfbytes bytes in use and numberOfbytes free bytes. Process will be Terminated

However, in this scenario, a new process is automatically started on the next user request. No administrative action is required.

To work around this problem, restart the World Wide Web Publishing service on the Exchange Server computer.

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