How to Backup Outlook OST File: Step-by-Step Guide (2025)

An Outlook OST (Offline Storage Table) file stores a local copy of your mailbox data, allowing you to access it offline. While you can't directly back up an OST file for reuse (as it is tied to your Outlook profile), you can back up its data by exporting it to a PST (Personal Storage Table) file. This blog helps you learn how to backup ost files in Outlook.

To back up an Outlook OST (Offline Storage Table) file, there are several methods you can use, including both manual and automated approach. Below are detailed steps for each method.

04 Easy Ways to Backup an Outlook OST File

Note: While backing up an OST file using the manual method, it is important to ensure that your internet connection is working properly. Otherwise, some emails or inbox contents might be missed.

Manual Backup Methods

#1: Use the Outlook Import/Export Feature

• Open Outlook Application on your system.
• Go to File > Open & Export > Import/Export.
• Choose Export to a file and click Next.
• Select Outlook Data File (.pst) and click Next.
• Choose the mailbox or folders you want to back up and click Next.
• Select a location to save the PST file.
• Set a password for the PST file (optional) and click Finish.

This process will create a backup of your OST data in PST format, which can be restored later if needed.

#2: Copy the OST File (Optional)

If you still want to back up the OST file itself:

• Navigate to its location:

Default path for OST: C:\Users\<YourUsername>\AppData\Local\Microsoft\Outlook

• Copy the OST file to your backup location.

Note: This is for archival purposes only; OST files cannot be opened directly without connecting to the original account.

#3: Use the Outlook Archive Feature

This method allows you to archive your emails, which can serve as a backup.

• Open Outlook app and go to the File tab.
• Click on Info, then select Cleanup Tools, and choose Archive.
• Select the files and folders to archive
• Choose a destination folder
• Click OK to start the archiving process.

Note: This method may not back up contacts.

Automated Backup Method Using Third-Party Tool (Recommended)

To directly extract or convert OST files to PST, use the Cigati OST to PST Converter. This tool allows you to export OST files into PST format, including emails, tasks, notes, and more.

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Steps to Back Up Outlook OST File Data:

• Download and install Cigati OST to PST Converter.
• Click Add File or Browse to locate your OST file.
• Select the file and click Open.
• Choose PST as the output format.
• Specify the save location for the PST file.
• Click Convert to start the process.

Conclusion

Backing up your Outlook OST files is crucial for data safety. You can choose between manual methods like exporting to PST or archiving, or opt for automated solution using Cigati OST to PST Converter software. Each method has its benefits, so select one that best fits your needs.

Frequently Asked Questions

How to copy Outlook OST file?

To copy an Outlook OST file, navigate to the file's location on your computer, typically in C:\Users\<Username>\AppData\Local\Microsoft\Outlook\, and copy the .ost file to your desired destination.

How to backup an OST file to PST?

Open Outlook, go to File > Open & Export > Import/Export, choose Export to a file, select Outlook Data File (.pst), choose the OST file data, and save it as a PST file.

How to backup an OST file in Outlook 2016?

In Outlook 2016, use the Import/Export feature under File > Open & Export > Import/Export, select Export to a file, and choose Outlook Data File (.pst) to create a backup.

Is it possible to recover my mail if OST file gets corrupted?

Yes, you can recover mail from a corrupted OST file by using the Cigati OST Recovery Tool.