An unexpected MAPI error occurred. Error returned was [].

This event can occur when attempting to start the Microsoft Exchange Event service. It means that the service could not be started because an unexpected error was encountered. The Error Code in the Description section of the event can be converted to a readable message using the ERROR.EXE program included on the Exchange Server CD ROM. This error code will usually provide information as to the underlying cause of the problem.

This issue can be seen if there are multiple “EventConfig_(Servername)” folders or if the “EventConfig_(ServerName)” folder is not replicated to the Exchange Server named “ServerName.”

Try the following steps to resolve this issue:

• Open Exchange System Manager and check if there is more than one instance of the same EventConfig_ServerName folder. If so, rename one of the instances so that both can be deleted. If you try to delete one while a duplicate exists, you get a warning tht indicates you must rename one of the folders. Delete both instances of the EventConfig_(servername) folder. Restart the Event service. This recreates a single instance of the EventConfig_(servername).
• Error Code 0x8000ffff indicates “catastrophic failure.” This usually occurs in mixed mode environments, where an Exchange 5.X server existed but is no longer present. In such a case, you can try to start the Event service using the 5.5 Service Account. In Exchange Server versions 2000 and later, the Exchange Server Services always start in the context of the Local System Account, unlike earlier versions where a “Service Account” was used to initialize the services.
• If there are multiple Exchange Servers, you should see one EventConfig(ServerName) Public Folder for each ServerName. Ensure that each of those Public Folders (also referred to as System Folders) has a replica on the server it corresponds to. So, for example, EventConfig(ServerOne) should have a replica on ServerOne and EventConfig(ServerTwo) should have a replica on ServerTwo.