Details
Product:Exchange
Event ID:2101
Source:MSExchangeIMAP4
Version:8.0
Symbolic Name:MoreThanOneFolderFound
Message:Duplicate folders %1 were detected in the mailbox for user: %2. Therefore the user's connection was disconnected.
User Action: To resolve this problem, the user should manually delete the duplicate folders by logging on to the mailbox using Outlook Web Access or a MAPI client such as Outlook.

For more information, see Help and Support Center at http://go.microsoft.com/fwlink/events.asp.
   
Explanation

This Error event indicates that folders that have the same name have been found in a mailbox. Microsoft® Outlook® may create duplicate folders when a mailbox user upgrades to Microsoft Outlook 2007. Until the duplicate folders are deleted, the affected mailbox user will be unable to retrieve e-mail using IMAP4 clients. The event description notes the specific duplicate folders that exist.

   
User Action

To resolve the error, the duplicate folders that were created by Outlook in the user's mailbox must be manually deleted. To delete the duplicate folders, the administrator or the user can logon to the affected mailbox using Microsoft Office Outlook Web Access or using a MAPI client such as Outlook and follow these steps:

  1. Switch to Folder List view.

    Look for the view option in the left bottom section of the UI.

  2. Delete the duplicate folders specified in the event description.

If you are not already doing so, consider running the tools that Microsoft Exchange offers to help administrators analyze and troubleshoot their Exchange environment. These tools can help you make sure that your configuration is in line with Microsoft best practices. They can also help you identify and resolve performance issues, improve mail flow, and better manage disaster recovery scenarios. Go to the Toolbox node of the Exchange Management Console to run these tools now. For more information about these tools, see Toolbox in the Exchange Server 2007 Help.