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
If you have a pst file in your profile you want to use for Calendar and Contacts, set the data file as the default then move any appointments or contacts in the 'This Computer Only' folders (steps are in Section B)
Follow the steps in Section A if you need to create a pst folder.
A. 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
B. Move Contents from the '(This Computer only)' folder to the folder in the *.pst file:
- Switch to the Calendar (This Computer only) folder
- Go to the View tab, select Change View
- Switch to a List view
- Select All and move or drag the appointments to the new calendar folder
- Repeat the steps above for Contacts, Tasks, and Notes if you have contents in those folders.
C. 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
Create a local pst file video tutorial
Folder order and Start up folder
After adding the pst file for calendar and contacts, you may want to rearrange the navigation pane, putting the IMAP account at the top and the Calendar & Contacts pst at the bottom.
I also recommend choosing a different start up folder if Outlook starts in the pst file's Inbox. Make this change in File, Options, Advanced. The option to choose a start up folder is near the top of the screen.
Using Safe PST Backup, you can back up your Outlook in any situation. Use Safe PST Backup for migration and the whole Outlook data files you have created will be backed up to the last date. Back up Email archive, Contacts, Calendar and other folders automatically. Incremental backup will be done regardless if Microsoft Outlook is running or not. New Safe PST Backup version 2.83 is fully compatible with Outlook 2019. Also, has backup files password protections.