I have a strange problem with a new installation of Outlook 2010 as a client against an Exchange 2013.
If you see the attached screen shot there are some identical folders in the left side which can not be removed.
I think that the user of the pc connected to these folders from his old pc, but if you check the account settings / email addresses in Outlook, these are NOT visible.
If you just try to close them from within Outlook you get the shown error saying something like
"This folder is connected to a user account. If you wan't to remove this account then go to Files and account settings and then remove this account"