Beginning with Outlook 2013, there are changes in how IMAP accounts are handled.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.
New Appointments are saved in the wrong calendar | Set reminders on Tasks in IMAP
Configuring special IMAP folders in Outlook 2013
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.
https://www.youtube.com/watch?v=j3f0lxBPhjU
Tools
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. Updated Safe PST Backup 3.00 allows to filter data by more parameters. Added single panel to set backup rules without configuration file |
THANK YOU DIANE! This worked for me!
I was able to use your instructions to create a .pst file on my old computer, transfer all my calendar and task items from my (this computer only) folder to the new .pst folders, then move that .pst folder to my new computer and set it up. THANK YOU!
Not only do I now have my calendar and task files on my new computer, but I can now COLOR CODE my calendar. AMAZING! I have been trying to figure out how to do this for 8 months! I was told my IMAP can not sync, nor can it support color-coding calendar entries. I never heard or saw a suggestion to use a .pst file. THANK YOU! I'm in business now!
By the way, I am using Microsoft 365 Apps for Business on Windows 10 Pro. On a 3-year-old Dell computer.
I've recently run into an issue where the Apple iCloud calendar and contacts won't sync with Outlook 365. I have been researching and trying to fix this for almost two weeks to no avail. Any ideas or new suggestions as to why this has started happening? It's worked fine for several years.
Hello - I am having problems restarting outlook 365 after deleting the .ost file. Upon restart Outlook stop responding, it looks like it re-created a new but incomplete .ost, I delete that new .ost and restart outlook again which now repopulates but the "This Computer only" folders are still there. Any idea what I am doing wrong?
Diane, I am using Office 20019 and successfully created a new calendar following your instructions to remove 'this computer only'. Everything works on my PC thanks to your instructions, but I cannot see / link to the new calender via Outlook.com or Microsoft Outlook for android app.
Can you suggest a solution for this problem as I can view / modify my emails on Outlook.com or Microsoft Outlook for android app.
Do you have the outlook.com account in your profile? If so, and if its the default data file, you would use its calendar.
Huge thanks, Diane. If you're able to answer this quicky, I'd be very grateful. My default .ost is my Hotmail address. If I use your detailed instructions above, will I then go on to delete all of my calendar contents and addresses from my Hotmail? Will I then be able to sync these across my mobile devices using the .pst file? Nervous as I'm self employed and my calendar is my income! Many thanks, Tony.
Diane you are a lifesaver! I've read a million articles about this problem and only yours works. After leaving a job, I had to transition from MS Exchange to Outlook 365, lose my corporate email and get my gmail personal address working in Outlook, all while not losing my contacts or calendar. You nailed it! Thanks again.
Hi Diane
I cannot see my calendar in the outlook mobile app on iphone, inbox and sent emails are fine. I am using outlook 365 on my pc with my default email account set up as IMAP. The calendar in outlook under "My Calendars" displays as : Calendar (This computer only). How can I setup outlook so that the outlook calendar will sync between PC and and mobile app. Calendar on mobile app appears to display gmail calendar not the outlook calendar.
Best instruction on how to fix the "(this computer only) issue. Thank you!