Moving Outlook's Exchange Mailbox Offline Cache

If you use Outlook and connect to an exchange mailbox and have the Use Cached Exchange Mode enabled. What Outlook does is create an offline cache (outlook.ost) to store a local copy of your exchange mailbox when your not connected. This offline cache is created in the Microsoft\Outlook folder underneath the Local Settings folder of your profile.

• XP and lower - C:\Documents and Settings\<Your Username>\Local Settings\Application Data\Microsoft\Outlook)
• Vista - C:\Users\<Your Username>\AppData\Local\Microsoft\Outlook

This location is fine if you have a lot of free disk space or your exchange mailbox isn't large but if get low disk space free notifications it might be time to move the offline cache to another location. The only problem is that moving the offline cache is not as simple as moving a Personal Folder this is due to Outlook storing the location of the offline cache with the exchange account settings.
Steps for moving a Personal Folder

1. Close Outlook
2. Locate the .PST file
3. Move it to the new location
4. Open Outlook
5. Use the dialog box to locate the Personal File at the new location

Steps for moving the offline cache

1. Close Outlook
2. Run Regedit and locate registry key HKEY_CURRENT_USER\Software\Microsoft\Office\<Version>\Outlook where <Version> is
   
   1. 10.0 for Outlook 2002
   2. 11.0 for Outlook 2003
   3. 12.0 for Outlook 2007
3. Add a new a string value called ForcePSTPath and enter the new location for the offline cache (from http://support.microsoft.com/kb/883401)
4. Run Mail Setup from the Control Panel
5. Click on the Data Files and add a new Temporary Personal Folder (this will just be temporary as outlook won't allow you to remove an account which is associated with the default email delivery location)
6. Set this Temporary Personal Folder to be the default delivery location. You may get a similar question just answer Yes
7. Open and close Outlook quickly. (This sets the Temporary Personal Folder created in Step 7 to be the default delivery location)
8. Back in the Mail Setup program and click on accounts and remove your Microsoft Exchange Account.
9. Open and close Outlook again to clear any settings. (May not be required but doesn't hurt)
10. In accounts (Step 8.) add your Microsoft Exchange account back.
11. Open Outlook and it will re-create the offline cache in the location specified entered in step 2.
12. Clean up by removing the Temporary Personal Folder created in step 7.
13. Open Outlook to recreate the offline cache in the new location.
14. Don't forget to delete the old offline cache from C: Drive.

Technorati Tags: Microsoft, Outlook, Exchange Cache Mode