The sign-in to Outlook Web App failed. User %1 has a mailbox on %2 server version. However, no Client Access server or front-end ...

The sign-in to Outlook Web App failed. User %1 has a mailbox on %2 server version. However, no Client Access server or front-end server with a matching version was found to handle the request.

For users on Exchange 2003, you can configure the Outlook Web Access URL for redirection using the Exchange2003URL parameter on the Set-OwaVirtualDirectory cmdlet on the Exchange 2010 /owa virtual directory.

For users on Exchange 2007, you can configure the Outlook Web Access URL for redirection using the externalURL and internalURL parameters on the Exchange 2007 /owa virtual directory.