The ResolveName function call does not return the MAPI_E_USER_CANCEL error code after you apply the 823719 hotfix for Exchange 2000 Server

After you apply and enable the hotfix that is described in the Microsoft Knowledge Base article 823719, if your MAPI program uses multiple threads to connect to and to use the MAPI address book provider, the ResolveName function call does not return the expected MAPI_E_USER_CANCEL error code. Instead, the threads stop responding and do not return as specified in the thread timeout value.

This symptom occurs when all the following conditions are true:

• Your MAPI program connects to a Microsoft Exchange 2000 Server mailbox store.
• Your MAPI program runs on either the Exchange 2000 server or on a member server that has access to Exchange 2000 Server MAPI components.
• Global catalog referral is enabled on the Exchange 2000 server.
• You have installed and enabled the hotfix that is described in the following Microsoft Knowledge Base article:
  
  823719  (http://support.microsoft.com/kb/823719/ ) Exchange 2000 MAPI address book provider cannot connect to a different global catalog server if the current global catalog server is unavailable
• Your MAPI program starts multiple threads that call the ResolveName function using the LPADRBOOK object that is retrieved by a call to the IMAPISession::OpenAddressBook method.
• The global catalog server that your MAPI program points to becomes unavailable.

When all these conditions are true, subsequent threads that are used to connect to and use the Exchange MAPI address book provider stop responding and do not return the appropriate error code. Also, the threads do not time out according to the thread timeout setting that you configured in the registry using the instructions in the Microsoft Knowledge Base article 823719. When the ResolveName function call returns, it returns a success code instead of the MAPI_E_USER_CANCEL error code.

This problem occurs because, when your MAPI program uses multiple threads in the ResolveName function, only one thread is permitted to access the MAPI address book provider. All other threads are blocked.

Update information

The following file is available for download from the Microsoft Download Center:

Download the Exchange2000-KB870540-v2-x86-ENU.exe package now. (http://www.microsoft.com/downloads/details.aspx?amp;amp;displaylang=en&familyid=363a57a4-8bed-4bbb-bbe4-abc11ab04611&displaylang=en)

Release Date: August 16, 2004

For additional information about how to download Microsoft Support files, click the following article number to view the article in the Microsoft Knowledge Base: Microsoft scanned this file for viruses. Microsoft used the most current virus-detection software that was available on the date that the file was posted. The file is stored on security-enhanced servers that help to prevent any unauthorized changes to the file.

Prerequisites

This update rollup requires Microsoft Exchange 2000 Server Service Pack 3 (SP3). For additional information about how to obtain the latest service pack for Exchange 2000 Server, click the following article number to view the article in the Microsoft Knowledge Base:

Restart requirement

You must restart your computer after you apply this update.

For additional information about the August 2004 Exchange 2000 Server post-Service Pack 3 update rollup, click the following article number to view the article in the Microsoft Knowledge Base:

Microsoft has confirmed that this is a problem in Microsoft Exchange 2000 Server.

For additional information about Microsoft software updates, click the following article numbers to view the articles in the Microsoft Knowledge Base: