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After you customize the behavior of Microsoft Office Outlook 2003 by using Microsoft Exchange Client Extensions, one or more Exchange Client Extensions events may not fire in a scenario where you expect them to be triggered. Therefore, your extension does not work as you expect.
This problem occurs if you use an IMAP profile with Outlook 2003. Outlook 2003's IMAP support does not support Exchange Client Extensions. Therefore, certain Exchange Client Extensions scenarios do not work correctly when you use an IMAP profile with Outlook 2003.
Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.
For additional information, click the following article number to view the article in the Microsoft Knowledge Base:
286408 Description of Outlook and Exchange client extensions
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