When you add an IMAP, Exchange, Outlook.com or Microsoft 365 (formerly Office 365) email account to MS Outlook, it creates a local offline storage table or OST file in the default location. OST, also called Outlook Offline Data File or Outlook Cache File, stores a synchronized copy of all your email items, such as emails, contacts, calendars, attachments, etc., on your local storage. It allows users to access their mail items even when the system is offline or not connected to the server.
It is not recommended to remove the default OST file as it may have serious consequences and lead to data loss. But sometimes it becomes unavoidable to delete OST file. Following are some common reasons that may force you to remove or delete the default OST file from your system to recreate or build a new one.
- Outlook slowdown or performance issue
- Slow search results
- Delay in sending or receiving email
- The email is stuck in the Outbox
- Outdated inbox
- Synchronization problems
In this article, you will learn how to safely remove the default OST file from your system to recreate a new one in Outlook client on Windows.
Steps to Safely Remove Default Outlook OST File
Follow the steps below in the given order to remove the default OST file from your system without any risk of data loss.
Step 1: Find the OST file
The default OST file is located in the %LocalAppData% folder location. To find the default OST, follow these instructions:
- Press Windows + R, type %LocalAppData%\Microsoft\Outlook and press Enter.
- This will open the location where the default OST files are stored.
Alternatively, you can open the Control Panel, search for and click Mail > Data Files.
This helps you find the OST file when you cannot access the Outlook options.
If you do not find your OST file in this location, it can be customized by an administrator or user via Group Policy (GPO) or manually via registry keys or during account setup. In that case, follow these steps:
- Open Outlook and right-click on your profile name in the left pane.
- Select Open file location.
- This will open a new File Explorer window showing the default location of the OST file.
Step 2: Create a backup of the default OST file
Before removing or deleting the default OST file, make a backup copy of the file. This helps avoid losing postal items in case something goes wrong.
To backup the OST file, copy it to another location. Make sure Outlook is closed when backing up the OST file. Otherwise, you may encounter an error.
If you have access to Outlook, you can also use the Outlook Import/Export Wizard to export mail items from the default OST file to Outlook-supported PST format. Follow these steps:
- In Outlook, go to File > Import & Export > Import/Export.
- Select Export to file and click Next.
- Select the Outlook data file (.pst) and click Next.
- Select the mail folders to export to PST and click Next.
- Press Browse to select a save location and click Finish.
- Enter password or click OK to save or export mail items from OST to PST.
Step 3: Remove default OST file
Once you have created a backup of the default OST file, you can remove it from the location. For this you need to close Outlook and make any of the following changes to remove and recreate the new OST:
- Delete the OST file
- Move (cut/paste) the OST file to another location
- Rename the OST file or its extension
After you perform these actions and start Outlook, the client will ask for the default OST. Since you have removed or renamed it, Outlook will create a new OST file in the same location. It will start synchronization, download all mail items from the mailbox server and store them in a new OST file.
It is possible that the newly created OST does not have all the email items or that the emails are missing. In such cases, you can use OST to PST converter software such as Stellar Converter for OST to convert the backup OST file into PST format that can be imported into Outlook and restore missing mail items such as contacts, email, etc. .You can also use the software to convert and export the OST file directly to an existing Outlook profile, Office 365 mailbox or Live Exchange Server.
Also Read: How to Transfer Email to Outlook from Any System
Conclusion
You should remove the default OST file only if you encounter errors related to OST or Outlook data file, performance issues, sync errors, etc. And that too after creating a backup of the OST file elsewhere. In this article, we have shared step-by-step instructions to help you safely remove the default OST file to recreate a new one.
To restore missing mail items, you can use an OST to PST converter such as Stellar Converter for OST. It also recovers deleted mail items and exports mail items from OST to Outlook profile, Office 365 or Live Exchange Server.
Read more By: Billy Willson, Software, Apps and Gadgets Expert
Categories: How to
Source: HIS Education