You cannot assign a delegate for your mailbox by using Entourage 2004 for Mac

When you try to assign a delegate for your mailbox by using Microsoft Entourage 2004 for Mac, you may experience one of the following issues:

• If your principal mailbox is located on a different Microsoft Exchange Server 2003 back-end server than the back-end server where the delegate's mailbox is located, you may receive the following error message:
  Entourage cannot delegate one or more items.
  An error occurred while contacting the Exchange Server.
• If your principal mailbox is located on the same Exchange Server 2003 back-end server as the delegate's mailbox, you may receive the following error message:
  Entourage cannot connect to the Exchange server.
  Make sure that your password was entered correctly and try again. (Error: 64927)

This problem may occur if there are duplicate display names in Active Directory that are hosted on your global catalog servers. Entourage 2004 for Mac uses packaged MAPI libraries to assign delegation rights on the Exchange Server 2003 mailbox. These MAPI libraries require that each mail-enabled Exchange Server 2003 user has a unique display name. Additionally, these MAPI libraries require that this unique display name is not being used by any other user account in the organization.

To work around this problem, use one of the following methods.

Remove duplicate display names from Active Directory

After you remove all the duplicate display names from Active Directory, use Entourage 2004 for Mac to assign a delegate for your mailbox.

Use Microsoft Outlook for Windows to assign a delegate for your mailbox

After you assign a delegate for your mailbox by using Outlook for Windows, you can use Entourage 2004 for Mac to access shared folders and mailboxes.

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