"HTTP 500 - Internal Server Error" Error Message When You Use Outlook Web Access to Connect to Your Microsoft Exchange Server 2003 Mailbox

When you try to use Microsoft Outlook Web Access 2003 to connect to your Microsoft Exchange Server 2003 mailbox, you may receive the following error message: Additionally, an event that is similar to the following event is logged in the application event log on your Exchange 2003 computer:

Event Type: Error
Event Source: MSExchangeDSAccess
Event Category: General
Event ID: 2050
Date: Date
Time: Time
User: N/A
Computer: Computer_Name
Description: Process Process_Name (PID=Process_ID). The shared memory heap could not be created.

This issue may occur when the Exchange virtual directory is either not running in the correct application pool, or when the ExchangeApplicationPool property has the incorrect identity.

To resolve this issue, make sure that the Exadmin, the Exchange, the Exchweb, the Exchweb\Bin, the Exchweb\Bin\Auth, the Microsoft-Server-ActiveSync, and the Public virtual directories are running in the Exchange Application Pool and not in the Default Application Pool. To do this, follow these steps:

1. Click Start, point to Administrative Tools, and then click Internet Information Services (IIS) Manager.
2. Expand Your_Server, and then expand Web Sites and Default Web Site.
3. Right-click Exadmin, and then click Properties.
4. In the Exadmin Properties box, on the Virtual Directory tab, make sure that the text in the Application pool list is ExchangeApplicationPool in the Application settings area. If the text is not ExchangeApplicationPool, follow these steps:
   1. Click Create, and then click ExchangeApplicationPool in the Application pool list.
   2. Click Apply, and then click OK.
5. Repeat steps 3 through 4 for the Exchange, the Exchweb, the Exchweb\Bin, the Exchweb\Bin\Auth, the Microsoft-Server-ActiveSync, and the Public virtual directories.

If ExchangeApplicationPool is in each Application pool list, this issue may be caused by an incorrect Identity setting for the ExchangeApplicationPool property. To resolve this problem, follow these steps:

1. In Internet Information Services (IIS) Manager, expand Application Pools.
2. Right-click ExchangeApplicationPool, and then click Properties.
3. Click the Identity tab, and then in the Select a security account for this application pool list, click Local System.
4. Click Apply, and then click OK.

You may find that Microsoft Server ActiveSync and remote procedure call (RPC) over Hypertext Transfer Protocol (HTTP) by using Microsoft Office Outlook 2003 still do not function. This problem occurs because Microsoft Web Storage System (WSS) sets the value of the NTAuthenticationProviders property for the default Web site to NTLM. This NTLM value must be removed from the NTAuthenticationProviders property. To remove the NTLM value, follow these steps:

1. At the command line, change to the \Inetpub\Adminscripts folder that contains the Adsutil.vbs file.
2. Run the following command to list the items for the default Web site:
   cscript adsutil.vbs enum w3svc/1
   
   
   The value for the NTAuthenticationProviders property is set to NTLM.
3. To remove NTLM as the value, run the following command:
   cscript adsutil.vbs set w3svc/1/NTAuthenticationProviders ""
4. To confirm that the value is empty, run the following command:
   cscript adsutil.vbs enum w3svc/1
5. Now test Server ActiveSync and Outlook 2003 by using RPC over HTTP.