DRS Softech

OST Viewer

Best Application to View, Open Outlook OST Files and Convert into PDF and Many Other File Formats

(Average Rating 4.9 Based on 753 Ratings)

Demo Version Limitation: The OST Viewer Tool free version only displays OST file content and saves only 50 emails per folder.

DRS OST Viewer Tool is the most trusted and genuine OST File Reader solution to read OST files without MS Outlook. You can check the Outlook mailbox items. Also, it allows you to save emails in PDF, PST, MBOX, EML, EMLX, MSG, CSV, HTML, and DOC. The software works well with both the Mac and Windows OS. This comprehensive utility provides options to exclude all the undesired mailbox items while converting the OST mailbox data.

  • Scan and open complete OST file content like inbox, sent, draft, outbox, trash, etc.
  • Access MS Outlook OST emails without MS Outlook installation.
  • Display a tree-structure preview of all mailbox folders of Outlook OST files.
  • Convert multiple OST files into PDF, PST, MBOX, EML, EMLX, MSG, CSV, HTML, and DOC file formats.
  • Remove duplicate email mail based on to, from, subject, bcc, and body.
  • Convert Outlook emails without email attachments to exclude unnecessary items.
  • Date filter feature for converting emails of a particular date range.
  • Simple and easy-to-use application for both technical and non-technical users.
  • Widely compatible with all versions of Windows OS.

When to Use DRS OST Viewer Tool

To Open Outlook OST File without MS Outlook

DRS OST Viewer Software helps you to open OST files without MS Outlook installation in your system. Therefore, if you have an orphan OST file that you want to access, you can use this OST reader tool. It displays the mailbox data in a hierarchical tree structure. You can choose any desired item from this mailbox preview.

To Convert OST file to Outlook PST File Format

Another reason to use the OST Data Viewer application is to convert OST to PST file format. This utility allows you to convert your Outlook OST file to PST and many other file formats like MBOX, EML, EMLX, MSG, PDF, CSV, HTML, and DOC. So, you can change your Outlook file to a widely supportable file type.

For Converting Accurate Outlook Mailbox Data

With this software, you can exclude all the unnecessary Outlook mailbox data and migrate only desired items. The application offers various features like duplicate email removal, Migrating without email attachments, date range mail filtering, etc. These features enable precise data migration.

Key Features of DRS OST Viewer Software

Comprehensive and Reliable Solution to Open and Convert Outlook OST Files
Open Outlook OST File

Open Outlook OST File

DRS OST Viewer Tool scans and opens the Outlook OST file. It helps you to access the OST mailbox folders without MS Outlook. Moreover, it supports OST files created by any version of MS Outlook or Exchange server.

Multiple File Selection

Multiple File Selection

One of the most prominent features of the OST File Viewer software is that you can add multiple Outlook OST files to the software and check the file content. You can also add a complete folder containing multiple Outlook OST files.

Preview Outlook Mailboxes

Preview Outlook Mailboxes

After you select the desired Outlook data file, you can check the preview of all the mailbox folders available in the Outlook OST files in a tree structure. You can check the emails in every mailbox folder. Also, you can choose specific items for conversion.

OST to PST & Other Formats

OST to PST & Other Formats

OST File Viewer Tool offers you to export emails from Exchange OST files and save them into several file formats including PST, MSG, EML, EMLX, MBOX, and document formats. The software allows you to open OST file without Exchange Server and Outlook application.

Exclude Duplicate Emails

Exclude Duplicate Emails

If your Outlook mailbox consists of duplicate emails, you can remove them during the OST file conversion. The application provides you Remove duplicate emails based on to, from, subject, bcc, and body.

Backup Emails without Attachments

Backup Emails without Attachments

If you do not want to migrate email attachments along with Outlook emails, opt for the Migrate or Backup Email without attachment files option. It skips all email attachments and converts emails only. It will reduce the mailbox size considerably.

Convert Attachments to PDF

Convert Attachments to PDF

When you select PDF file format as the destination, this OST to PST Converter tool provides you with the convert attachments to PDF feature. Using this option, you can convert the Outlook email attachments to PDF file format.

Date Filter Feature

Date Filter Feature

Another prominent feature of the DRS OST Viewer Tool is the Date Filter feature. It enables you to convert emails of a particular date range without considering the remaining mailbox items. Therefore, you can save only necessary items.

Free Demo Version

Free Demo Version

You can download the free demo version of the OST File Reader. It enables you to preview all the emails in selected OST files and convert 50 emails per folder. Therefore, you have to purchase premium software for complete file conversion.

Windows Compatible Tool

Windows Compatible Tool

DRS OST Reader Tool is widely compatible with all versions of Windows OS. Also, this application supports all versions of OST files. So, you can install and use the application on your PC whether you have Windows 11 or any other old version.

Screenshots - DRS OST File Viewer Tool

Download Outlook OST Viewer Software

Best OST File Opener Tool to Read Outlook OST Files and Convert them into PDF, PST and Many other File Formats

Software Download

DRS OST Viewer Tool helps you open Outlook OST files without MS Outlook installation. It also enables you to convert your OST file to distinct file formats like PST, PDF, MBOX, EML, MSG, and many other file formats. Built with advanced features and an intuitive GUI, it is the best OST File Viewer software.

Size: 158 MB   Version: 23.3

Download Now Purchase Now

DRS OST Reader is a freeware for accessing OST files and converting them into various file types. Its free version can only convert 50 emails per folder. You have to purchase the premium license for complete migration.





Hard Disk Space

500 MB Free Space

supported Editions

1. Why is the software not working in my Windows 10?

Ans: Follow the steps below if the software is not working properly on your PC.

  1. Go to Windows Defender.
  2. Click on Settings.
  3. Turn off Real-Time Protection.
    Without disabling the controlled folder access, the application becomes unable to install some essential programs. It is because the safety feature blocks anything that tries to modify user\{user name} or various other related folders.

2. Why is my backup process still getting blocked?

Ans: Disable the antivirus and Windows defender and add the product to the exception list. The firewall and antiviruses that protect your system from malicious programs also consider our product a threat. So, you need to deactivate the security features.

3. Does this software support SAN, NAS storage systems?

Ans: Yes, the tool supports SAN, NAS storage systems provided that the file's access is transparent.

Frequently Asked Questions

You can open OST files via the DRS OST Viewer Tool by following the below steps.
  • Download and install the DRS OST File Viewer. Run it as administrator.
  • Now, click on the Select Files button and choose the desired OST file. Press Open.
  • The file has been added to the list. Click on the Next button.
  • Check the mailbox preview and select desired items. Press Next.
  • Choose the destination file format in the Save/Backup/Migrate As field.
  • Select the other file conversion options as per your requirement.
  • At last, click on the Convert button to start file conversion.

Yes, the application allows you to convert multiple OST files at once. You can choose as many files as you want. Also, you can open an entire folder containing multiple OST files.

There is no file size limitation in this application. It can convert Outlook OST files of any size.

If the OST file won't open in MS Outlook 2016 or any other version, chances are high that your data file has been corrupted. You must repair the corrupted OST file using the OST recovery tool.

The application enables you to convert OST to PST file format. Along with that, it can also convert your Outlook OST file to various file formats like PDF, MBOX, EML, EMLX, MSG, CSV, HTML, and DOC.

DRS OST File Viewer Open Source software is not available. You can only download and purchase the software from the official website of DRS Softech. Microsoft OST Viewer Tool freeware allows you to view OST file content for free but converts only 50 emails per folder. You have to purchase the premium license for converting complete mailbox data.

Yes, the application shows whether the email has an attachment or not but it does not enable you to open it. You can convert them into PDF file format while selecting PDF as the destination.

The software will run smoothly on your Windows 11 PC. It has advanced algorithms to operate efficiently on any version of Windows OS.

Words By Our Clients

DRS OST Viewer - Freeware v/s Full Version
Product Features Free Version Premium Version
Open Outlook OST file content without MS Outlook
Convert OST file to PDF, PST, MBOX, MSG, EML, EMLX, HTML, CSV and DOC Save only 50 emails per folder Complete mailbox
Display Outlook mailbox folder in a tree structure
Exclude duplicate emails during the file conversion
Backup emails without attachment files
Save attachments separately
Date filter option to migrate emails of a particular date range
Customize folder name and destination of the resultant file
Widely compatible with all Windows versions
24*7 technical support
Price Free $49
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