What Happens if you Delete the Outlook OST File?

Microsoft Outlook is a widely used email client that helps millions of users manage their emails, calendars, and tasks seamlessly. Behind the scenes, Outlook relies on various files to store and synchronize data, and one such critical file is the Offline Storage Table (OST). The OST file allows users to access their emails even when offline and plays a crucial role in synchronizing data with the Exchange server.

In case the OST file becomes inaccessible or gets deleted mistakenly, you won’t be able to access your Outlook emails. The reliance of MS Outlook on OST files is so important that deleting it can cause several OST file errors. In this blog post, we’ll explore the consequences of deleting OST files from Outlook and also understand whether it is safe to do or not along with the potential solutions for recovering from such a situation.

Understanding the Outlook OST File:

The OST file serves as a local cache for your mailbox data, allowing you to work with your emails, calendar events, and other items even when you’re not connected to the Internet. This local copy helps improve performance and responsiveness, especially for users with slow or unreliable internet connections.

Can you Delete the OST File? Causes and Consequences

Yes, you can delete the Outlook OST (Offline Storage Table) file, and there are various reasons why someone might choose to do so. However, it’s essential to understand the consequences and potential impact on your Outlook data and workflow before deciding to delete this file.

NOTE: If you are unable to find the OST file location then probably it is hidden. You can unhide the file first and then tries to delete it.

Here are some scenarios where users might intentionally delete the OST file:

Corruption Issues: If your OST file becomes corrupted or damaged, it can lead to OST file synchronization errors in Outlook. In such cases, deleting the OST file can be a troubleshooting step to resolve the corruption.

Outdated or Inaccurate Data: The OST file serves as a local cache, and sometimes the data within it can become outdated, or inaccurate. Deleting the file prompts Outlook to recreate it, ensuring a fresh and accurate synchronization with the Exchange server.

Insufficient Disk Space: OST file size can grow over time, especially for users with large mailboxes. If you’re running low on disk space, deleting the OST file can free up considerable space. However, it’s essential to consider alternative solutions like archiving or compacting OST file size to manage space more effectively.

Removing old OST Files: You may have old backups of OST files that you intentionally want to delete. Doing this is safe and does not need any skills.


Loss of Offline Access: Deleting your OST file means you lose the ability to access your mailbox data offline. Without the local cache, you won’t be able to view emails or make changes to your calendar when not connected to the internet.

Recreation of OST File: Outlook will automatically recreate the OST file the next time you open the application and connect to the Exchange server. However, this process can take some time, depending on the size of your mailbox. During this time, you might experience delays and temporary unavailability of your mailbox data.

Initial Synchronization: After recreating the OST file, Outlook will need to synchronize your entire mailbox, which can be time-consuming and might impact your computer’s performance. This process may also consume additional bandwidth.

Potential Data Loss: While the OST file primarily acts as a cache, it may contain some data not yet synchronized with the server. Deleting the OST file could result in the loss of recent changes or emails that have not been uploaded to the server.

How to Safely Delete the OST File?

Although deleting OST files is a very simple process, there are a few things to take into consideration while doing it. Follow the complete step-by-step process to safely remove the OST file from your device:

Close Outlook: Ensure that Outlook is completely closed before attempting to delete the OST file. You can check the Task Manager to make sure no Outlook processes are running in the background.

Locate the OST File: The default location of the OST file depends on your Outlook version and Windows operating system. Common paths include:

Outlook 2019, 2016, 2013, and 2010 on Windows 10:


Outlook 2010 on Windows 7 or Vista:


Delete the OST File: Find the OST file (usually named after your email profile), right-click on it, and select “Delete” from the context menu. Alternatively, you can move it to the Recycle Bin.

Reopen Outlook: After deleting the OST file, reopen Outlook. The application will automatically recreate the OST file during the next synchronization with the Exchange server.

Considerations and Caution:

Data Loss Risk: Deleting the OST file means you might lose any changes or data that haven’t been synchronized with the server. Ensure that important data is backed up or synced before proceeding. For this, you can turn OST backup into PST file format because PST files can be used in any MS Outlook profile on any device with any issue.

Internet Connection: A stable internet connection is necessary for Outlook to synchronize with the Exchange server and recreate the OST file. The process may take some time, especially if you have a large mailbox.

Backup: If possible, consider backing up your OST file before deleting it, especially if you have concerns about potential data loss. While deleting the Outlook OST file is possible and sometimes necessary for troubleshooting, it should be done with caution, and users should be aware of the potential consequences. Always consider alternatives and backup measures before taking such actions.

How to Recover Deleted OST File?

If you’ve unintentionally deleted your Outlook OST file, there are steps you can take to recover from this situation:

Check the Recycle Bin: Start by checking the Recycle Bin on your computer. Deleted OST files might be recoverable from here.

Restore from Backup: If you have a backup of your computer or the Outlook profile, you can restore the OST file from the backup. Regular backups are essential for safeguarding your data.

Use OST to PST Conversion Tools: You can use Magus OST to PST converter, allowing you to extract data from the deleted OST file. Once recovered, you can import the PST file into Outlook.

Recreate Outlook Profile: As a last resort, you can recreate your Outlook profile. This involves removing and reconfiguring your email account. Keep in mind that this process might lead to some data loss and will require resynchronization.


Deleting your Outlook OST file can have several consequences, but with the right precautions and recovery steps, you can minimize the impact on your workflow. It’s crucial to regularly back up your data and be cautious when handling sensitive files. By understanding the implications of deleting the OST file, you can take proactive measures to ensure a smooth recovery process if such a situation arises.

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