When you try to open your mailbox on a Microsoft Exchange Server 2010 server by using Microsoft Outlook, you receive one of the following error messages:
Cannot open your default email folders. The attempt to log on to Microsoft Exchange has failed.
Outlook cannot log on. Verify that you are connected to the network and are using the proper server and mailbox name.
Cannot open your default e-mail folders. The file path_to_OST is not an offline folder file.
This issue occurs when one of the following conditions is true:
The Exchange Server 2010 Mailbox role and the Exchange Server 2010 Client Access Server (CAS) role are installed on the same server. Therefore, the address of this server is referenced by the RpcClientAccessServer mailbox database property. When you uninstall the Exchange Server Server 2010 CAS role from this server, the RpcClientAccessServer property is not changed. The mailbox database property still references the original Exchange Server 2010 server address, even though Exchange Server 2010 CAS is not installed on that server.
You uninstall the Exchange 2010 CAS role from the server. However, the uninstall process does not completely remove all the settings. The RpcClientAccessServer mailbox database property still references this server address.
The LegacyExchangeDN attribute in the database is changed to an incorrect value.
To resolve this issue and to change the RpcClientAccessServer mailbox database property to the correct value, follow these steps:
NoteDuring this process, the LegacyExchangDN attribute is updated to the correct value for the Exchange Server server.
Click Start, point to All Programs, point to Exchange Server 2010, and then click Exchange Management Shell.
At the command prompt, type the following cmdlet and then press ENTER:
The returned value may not be the Full Qualified Domain Name (FQDN) of the Exchange Server 2010 CAS server or of the Exchange Server 2010 CAS array. If this behavior occurs, type the following cmdlet and then press ENTER: