Instead of using two data files, one for IMAP email and one for your calendar and contacts, Outlook 2013 uses an .ost file for IMAP accounts and stores appointments, tasks, contacts, and notes in the IMAP data file, in folders labeled "(This computer only)".
While users with just one email account in their profile may like having only one data file, it's really not in most user's best interest to use the IMAP .ost file for calendars and contacts.
This is problematic for a number of reasons, including the fact that you can't move an IMAP .ost file to another computer or profile. You need to export the contents of the non-mail folders to a .pst file to move them to a new computer (or a new profile). You can't backup the .ost and easily recover the appointments and contacts from it. You need to export the folders on a regular basis to back them up.
In addition to the issues involving backing up or moving your calendars and contacts, you also won't be able to set a range of flags and reminders or use Categories on the items stored in the IMAP .ost file.
The solution? Use a .pst file for your calendar and contacts. If you have a POP3 account in your profile, set it as default and move your calendar and contacts to the folders in the pst file. You can remove the (This computer only) folders by closing Outlook, deleting the IMAP .ost file then reopening Outlook. It will create a new .ost file without the special Outlook folders.
Create a local pst file
To create a local pst file:
- Go to File, Account Settings, Data Files tab
- Click Add, type in a name for the pst file
- Set it as Default data file
- Close Outlook and reopen it
- Move the contacts from the Contacts (This Computer only) folder to the Contacts folder in the new pst file
- Switch to the Calendar (This Computer only) folder
- Switch to a List view
- Select all and move or drag the appointments to the new calendar folder
Repeat Step 5 for Tasks and Notes, if necessary.
To remove the (This Computer only) folders from the IMAP data file:
- Close Outlook.
- Open Windows Explorer, type %localappdata%\microsoft\outlook in the address bar
- Delete the IMAP ost file
- Restart Outlook