How to Open OST File without Outlook and Exchange Server?

  Rollins Duke
Rollins Duke   
Published: April 29th, 2025 • 8 Min Read

There are some situations, due to which several users prefer to open OST file without Outlook. If you are also looking for an excellent way to open an OST file without Outlook, this blog post explains 3 free methods to resolve users’ queries.

First, if you have an orphan OST file then there is no option available to import OST file into Outlook. However, if you have an OST file connected to Outlook and Exchange Server then a hope is available for opening .OST files without Outlook.

The upcoming article discloses 3 best practices to access connected and orphan OST files without Outlook client. But first know some possible reasons and situations to do that.

Understand about OST Files

Aspect Details
Full Forum OST stands for offline storage table.
Purpose Stores a local copy of mailbox data from Exchange, Office 365 or IMAP Accounts for offline access.
Created By Automatically generated by Microsoft Outlook when using Cached Exchange Mode.
Content Stored Emails, contacts, calendars, tasks, notes, and other mailbox data
Offline Functionality Allows users to work offline, changes sync automatically when connectivity is restored.
File Location Saved locally on your system, usually under Outlook profile folder.
Accessibility Limitations Tied to a specific Outlook profile cannot be opened directly on a different system or without an original account.

Reasons to Open OST File Without Outlook?

No Outlook Access: You might not have Microsoft Outlook installed on your computer. But you need to access the emails stored in an OST file.

Outlook Crashed: If your Outlook crashed and is unable to start then various professionals wish to open OST file without Outlook client.

Switching Email Client: When a user decides to switch email client then he wants to access OST files without Outlook desktop client.

Legal & Forensic: Sometimes forensic investigators find OST files during the raid, and they want to access them without Outlook to analyze OST files for evidence.

Locate the OST file location in your System

You can locate OST file by Outlook default location and also detect OST location using Outlook account setting as we have explained below:

Method 1. Open OST File Default Location

  1. Press “Windows+ R” and click on open
  2. Now, for Microsoft Outlook 2016, 2019 and Office 365: C:\Users\\AppData\Local\Microsoft\Outlook\
  3. Outlook 2013 and earlier: C:\Users\\AppData\Local\Microsoft\Outlook\

Method 2. Using Outlook Account Settings

  1. Open Outlook and navigate to the file.
  2. Press on “Account Settings” and Select your Account.Click on Account Settings
  3. Now, Choose “Data file” and see the path of the OST file.Select data files

How to Access OST File Without Outlook Manually?

  1. Launch Microsoft Outlook and export data in PST.
  2. Copy and paste exported PST from Windows to Mac.
  3. Use the inbuilt option to import PST file in Mac Outlook.
  4. Drag and drop emails from Mac Outlook to EML format.
  5. Open EML files without Outlook using Thunderbird, eM Client, etc.

Manual Method Limitations to Open OST File Without Outlook?

  • OST file should be connected to Outlook or Exchange Server in offline mode.
  • Microsoft Outlook desktop client should be in proper working condition.
  • It requires Mac Computer, and Mac Outlook to perform this task.
  • Need to complete above mentioned 5 phases and each phase has multiple steps.
  • It requires technical knowledge to open .ost files without Outlook.

Pro Method to Access OST File Without Outlook

Free OST Viewer Software is obtainable for Windows and Mac OS users which is specially developed to access orphan OST files without Outlook. This tool supports all the latest Windows and Mac OS. This application is compatible with OST files of Microsoft 2021, 2019, 2016, 2013, 2010, 2007, and previous versions. Even this is an easy-to-use software so all technical and non-technical users can utilize it to open OST file without Outlook.

How to Open OST File without Outlook? Simple Steps

  1. Start the software on your computer and click Add File.
    Add File option
  2. Pick an OST file from your machine and press the Open button.
    Click Open
  3. Now, you can open OST file without Outlook, you can access its data.
    Open OST file without Outlook
  4. Choose the Attachments tab in the software GUI and see the attachments.
    Open OST files without Outlook with attachments
What Are Software Benefits to Access OST File Without Outlook?
  • Standalone software to open OST files without Outlook as well as any other email program.
  • This is 100% freeware software, and you can use it to access unlimited OST files without Outlook.
  • An excellent utility for opening .ost files without Outlook with emails, contacts, calendars, tasks, notes, journals, and all.
  • It shows OST file data in the software panel with the actual folder and sub-folder structure.
  • The tool has an isolated option to open and extract OST attachments separately in actual formatting.
  • Highly recommended software for home users who don’t want to spend money.
Alternative Method to Open OST File without Outlook

OST Converter Software is an all-in-one solution that is highly suggested for professional and enterprise use. This tool is also compatible with Windows and Mac Operating Systems. It comes with a free trial version that allows you to convert 25 items from each folder in 30+ saving options.

Business professionals use this software to open OST files without Outlook in several email applications. Even this software has direct options to import OST to Yahoo Mail, Gmail, Microsoft 365, and other web-based email services.

What Are Alternative Method’s Advantages?
  • A great choice for opening .ost files without Outlook as it permits you to convert OST to PST, EML, MBOX, PDF, DOC, XPS, etc. so after conversion, you can open them with associated programs.
  • This software asks only for webmail account credentials when you have a desire an open OST files with Outlook in web-based email services. Hence, you can save your crucial time and effort.
  • Enable Use Recovery Mode option which is specially added to repair corrupted OST files before opening them without Microsoft Outlook client.
  • This utility automatically adds OST files in the software panel from a default storage location. Even, you can also use the Select Files or Select Folders option for adding OST files from different locations.
User Questions with Expert Reply

Q 1: How do I open an OST file without Outlook?

Scroll up this article to get a reliable solution to open an OST file without Outlook. Above we have explored 3 best ways to resolve this problem.

Q 2: How to find my OST file location on my computer?

  1. Run Outlook on your computer and choose the File option.
  2. Then select Info >> Account Settings >> Account Settings.
  3. Click Data Files and then choose an OST file.
  4. Select the Open File Location option and open location.

Q 3: Can I open multiple OST files without Outlook using your software?

Yes, you can open unlimited OST files without Outlook using BitRecover.

Best Practices for Managing OST Files
  • OST files can be large and prone to corruption, especially if Outlook crashes. Regular backup OST file to keep secure important data.
  • OST files are typically linked to specific Outlook profiles and can be difficult to access when moving to another system. It allows for easier access and portability especially if you want to open their old OST file and want to switch to a new Outlook profile.
  • If an OST file corrupted, Outlook inbuilt Inbox Repair Tool can help to restore minor corruption. Regularly using this tool can prevent data loss and keep your OST files in healthy conditions.
  • Modifying OST files directly can cause corruption or data loss. Always open an OST file through Outlook.
  • OST files become larger, especially if you have a significant amount of email data. Make sure your hard drive has enough storage to manage these files without any issues. Consider cleaning up unnecessary data or archiving older emails to maintain file size.
  • Enabling Cached Exchange Mode in Outlook allows your OST file to be synchronized with the server while keeping a local copy of your emails. This improves access speed and ensures always having a backup of your emails, even when offline.
  • Old or unused OST files can accumulate overtime and take valuable storage periodically to review and delete outdated OST files that are no longer required, making sure to backup important data before deleting.
Conclusion

Now choose an excellent way to open OST file without Outlook, we have discovered the top 3 methods. If you are a home user and want to access OST files without Outlook free, then opt for 2nd method. In case you are a business professional, then you can go with an alternative technique explained above. If you have any other queries, then contact our technical support team.