I am trying to open another users exchange 2007 mailbox in Outlook 2007. I have added it as an additional mailbox to open in Outlook. When trying to open the their folder (clicking the + sign) I get a message "Can't expand folders". I am the admin and have set myself to have full access permission the their mailbox, closed Outlook, Re-booted. No luck. I try giving myself full permission to another users mailbox and it popped right up with not problems. I have deleted my local ost file and let Outlook re-build it, still no luck. Any suggestion of what to try next?