How to change Outlook OST file location using Group Policy

Read time 4 minutes

The Offline Storage Table (OST) file is the repository for storing mailboxes associated with Exchange Server on-premises and Microsoft 365 accounts. Other IMAP accounts like Hotmail, Yahoo, etc. also store the synchronized mailboxes in OST files. Its significance lies in the fact that the mailbox remain accessible and available when there is no connection between Outlook and the server.

The default saving location of OST file is following –

• C:\Users\AppData\Local\Microsoft\Outlook
• C:\Documents and Settings\Local Settings\Application Data\Microsoft\Outlook

Microsoft has fixed the size of an OST file at 50 GB. However, experts advise to keep the size of OST file at an optimum level where it does not slow down Outlook or fill the storage in C drive. The following article will cover some methods in which you can change the location of OST file using Group Policy and gain some useful space.

How to change OST file location in Outlook 2019, 2016, and 2013

In Windows Server platforms where Active Directory Services are developed by Microsoft, Group Policy Management Console plays an important role of an Administrative tool to manage complete environment. For such Outlook-based Exchange accounts in which cached mode is turned on, there is an option to change the OST file location using available GPO settings. Following the below steps –

1. In Windows Server, go to application and choose Group Policy Management too. Open it.
2. Expand the Domains showing your current domain and go to Group Policy Objects option.
3. Right-click to Default Domain Policy and click Edit. it will open Group Policy Management Editor.
4. In Group Policy Management Editor, go to Administrative Template under Policies category.
5. Expand Microsoft Outlook 2016, then miscellaneous and double-click on Default location for OST files.
6. Click on Enabled option to enable the setting to change the default location for OST files. Then, click Apply button.
7. Input the new location for the OST file and click OK.

There are many Outlook related settings you can change using Group Policy. Some of them are mentioned here:

• Cached Exchange Mode Settings
  This feature allows Outlook to locally synchronize email messages based on their message date. By default, Outlook syncs messages from the past 12 months. If you wish to remove this restriction, you can access the settings and choose All from the synchronization options list.
• Disallow Download Full Items
  It turns off the Download Full Items option for Outlook.
• Disallow Download Headers
  It turns off the Download Header option in Outlook.
• Disallow Download Headers the Full Items
  It turns off the Download Headers then Full Items in Outlook.
• Disallow Download Headers the Full Items
  It turns off the Download Headers then Full Items in Outlook.
• Disallow On Slow Connections Only Download Header
  It turns off the On Slow Connections Download Only Headers option in Outlook.
• Download Public Folder Favorites
  It synchronizes Public Folder Favorites in Cached Exchange Mode.
• Download shared non-mail folders
  It synchronizes shared non-mail folders in the Cached Exchange Mode.
• Use Cached Exchange Mode for new and existing Outlook Profile
  It configures new and existing Outlook profiles to add in the Cached Exchange Mode.

Final words

Modifying the location of the OST file can prove beneficial in specific scenarios; however, it is not always an ideal solution, as it carries the risk of file corruption or inaccessibility. During the relocation process, users may inadvertently delete data from the OST file or even delete the file itself. While group policies assist in changing the OST file location, they may introduce accessibility challenges. In the event of errors, resorting to the ScanPST tool becomes necessary, as it can scrutinize the OST file for minor corruptions.

Considering the potential limitations of the ScanPST tool, opting for a professional alternative appears to be a prudent choice. Kernel for OST to PST Converter offers a robust solution for swiftly recovering inaccessible and deleted items from a corrupt OST file. If you find yourself unable to open or access data within an OST file, this software can assist you in retrieving those items. Furthermore, it allows for seamless integration of the resulting PST file into Outlook, ensuring a smooth transition after the OST to PST conversion process.