If you want to open OST file in Outlook, read this article carefully. Here, we explain different methods to access your Outlook OST file. Moreover, we recommend the professional OST Viewer Tool. It helps you to open the OST file and access your complete mailbox.
Outlook OST files are the Offline Storage Table that stores your complete Outlook profile in your system. It has great significance because the corruption of OST files will lead to numerous Outlook issues. You might not be able to access the mailbox in the MS Outlook application. Sometimes, you are required to open inaccessible OST file in Outlook. Various options are available to access your Outlook data.
If you want to know, ‘How do I open an OST file without Outlook?’ The answer is via a professional OST viewer tool. It helps you to open the OST file whose corresponding email account has been removed from MS Outlook. You can also convert OST to PST, PDF, HTML, and many other file formats.
Why Does One Need to Open OST File?
Generally, an OST file automatically gets created when you configure an email account in Outlook, and it syncs with the exchange server. However, it might be possible that someone sent you an OST file or you have permanently deleted the email account from the server, but the associated OST file has remained. In such scenarios, you will require to open the OST file.
Opening an active Outlook OST file is not a big deal. But, to access your mailbox items, even if you have removed the email account from Outlook, you need to convert it to PST file format. After that, you can open the mailbox data when needed. Also, it will help you restore your emails in case of data loss.
Another scenario is when the OST file belongs to an email account configured in Outlook, but the OST file won’t open in MS Outlook. Here, it might be possible that the OST file is corrupted. You must repair the damaged OST file through the advanced OST recovery tool. After that, you can easily access your emails and other items.
How to Convert an OST file With MS Outlook?
To open OST file, you must convert it into a PST file format. You can easily import OST file which is associated with an active Outlook account into PST format. It also helps you to restore your mailbox data in case of accidental deletion. However, if you want to open an orphan OST file, the manual solution will not work. The only solution is to use professional software. First, we will discuss how to convert Outlook OST file to PST file format in MS Outlook.
- Open MS Outlook in your system.
- Click on the File button in the top menu bar.
- After that, select the Open & Export option and choose the Import/Export icon.
- In the Import and Export wizard, select the Export to a file option and press Next.

- Choose the Outlook data file (.pst) option and hit Next.
- Select the Outlook mailbox folder that you want to export and click Next.
- At last, define the saving location to the PST file and press the Finish button.
It is the method to back up your Outlook OST file mailbox to PST file format. However, this procedure will only work when the OST file is associated with an email account synchronized in Outlook. You cannot convert an orphan OST file with this method. So, in the next section, we will explain how to convert OST to PST via a professional tool.
Open OST File without Outlook Application
DRS OST File Reader is a highly recommended and secure solution to open orphan OST files. An OST file that is no longer available on the server is known as an orphan OST file. The OST file viewer application enables you to open the OST file and display all the available mailbox items in the Outlook data file. Using this utility, you can also convert OST to PST, MBOX, EML, EMLX, MSG, PDF, CSV, HTML, and DOC file formats. Moreover, it enables you to exclude duplicate emails and attachment files.
Steps to Open OST file via OST Viewer Tool
Follow the below instructions to convert OST to PST file format.
- Download and install the DRS OST File Viewer Tool. Run it as administrator.

- Press Select File, choose the desired OST file, and hit Open.

- Check the mailbox preview and tick the items you want to convert. Press Next.

- After that, select PST file format in the Save/Backup/Migrate As field.

- Now, choose the remaining file conversion options and click the Convert button.

Conclusion
You can open OST file with MS Outlook when the data file belongs to an email account configured in Outlook. Another important thing is that you must convert OST to PST file format, so you can easily access Outlook mailbox folders and also restore them if required. To access the mailbox data of an orphan OST file, you will need a third-party OST Viewer tool because a manual method available that can open an orphan OST file is not available.