First, if I transfer the offline data file xxx.ost from one computer to the other, Outlook 2013 tells me that the file belongs to a different mailbox and has to start a After upgrading to Outlook 2013, however, I haveĮncountered a series of problems with Outlook when I switch between the two computers. I have been using the cashed mode in Outlook 2010 in both my office and home computers by transferring the offline data file xxx.ost between the two computers every time when I switch from one to the other.