Convert OST to MSG for Enterprise Email Archiving and Migration
User Query: My Outlook profile crashed after Windows was reinstalled. I still have the old OST file, and I need to save a few important emails as individual MSG files. So I can open and share them later. Is there any way to convert OST files to MSG without losing email formatting or attachments?
Introduction: Many Outlook users face this problem after a system crash, profile corruption, mailbox deletion, or computer replacement. They still have the OST file but cannot access individual emails when they need to share or archive them. In such cases, converting OST to MSG becomes the easiest solution. MSG files store a single Outlook email with all its original details, including attachments, formatting, metadata, and properties. This guide explains the best ways to convert OST to MSG, including the manual method and a professional DRS Softech OST File Converter for secure conversion.
Quick Solution to Convert OST File into MSG
If your OST file is connected to Outlook and accessible, you can save emails individually as MSG files. However, if the OST file is orphaned, inaccessible, or contains thousands of emails, using an OST to MSG Converter is the fastest and safest solution. Steps:
- Download the DRS Softech OST Converter Tool.
- Add your single or multiple OST files. Click Next.
- Preview and select the OST files with the search option.
- Choose MSG as the Saving Format from the list.
- Apply general and advanced features as needed. Press Convert.
Reasons to Export OST to MSG
- Instead of exporting the entire mailbox, users can save only selected emails.
- MSG files can be shared with colleagues while preserving the original email format.
- Many organizations store important emails individually for audits and legal investigations.
- Saving important messages separately reduces the risk of accidental deletion.
- If Outlook no longer opens the OST file, converting it helps recover important messages.
Can You Transfer OST Files to MSG Manually?
Yes, but only under specific conditions. The manual method works only if:
- Outlook opens normally.
- The OST file is connected to the original Outlook profile.
- The mailbox is accessible.
- If the OST file is orphaned or Outlook cannot open it, the manual method will not work.
Method 01: Convert OST to MSG Using Drag and Drop
If your OST file is connected to an active Outlook profile, you can save individual emails as MSG files using the drag-and-drop method. Steps to Follow:
- Open Microsoft Outlook and go to the mailbox connected to your OST file.
- Browse to the folder that contains the email you want to export.
- Select the required email and open the destination folder on your Windows or Mac computer.
- Then, click and hold the email, then drag it from Outlook to the destination folder or desktop.
- In the end, release the mouse button. Outlook automatically saves the email as an .msg file.
Note: This method only works for OST files that are connected to an active Outlook account. It is not suitable for orphaned, damaged, or inaccessible OST files.
Method 02: Convert OST Files to MSG Using the Save As Option
Outlook also provides a built-in Save As feature that lets you export individual emails as MSG files. Steps to Follow
- First, launch Microsoft Outlook and open the mailbox linked to your OST file.
- Double-click the email you want to save so it opens in a separate window.
- Click the File tab and select Save As.
- In the Save as type drop-down menu, choose Outlook Message Format (*.msg).
- Select the folder where you want to save the MSG file.
- Lastly, click Save to complete the process.
Note: This method can save only one email at a time and requires Outlook to be installed and connected to the original mailbox. It cannot convert orphaned OST files.
Professional Method to Convert OST to MSG
If your OST file is orphaned or contains thousands of emails, using a professional converter is the most reliable approach. The DRS Softech OST to MSG Converter allows users to convert healthy, orphaned OST files into multiple file formats, including MSG. Preserving the original mailbox structure. It is suitable for both home users and enterprise administrators. Option to convert OST to MBOX and several other file formats.
Features included in the OST Converter Tool:
- Batch Conversion: Convert single or multiple OST files with 100% accurate results.
- Saving Formats: Convert OST to PST, EML, CSV, VCF, MD, JSON, and other file formats.
- Preview option: Cross-verify the added OST files/folder before conversion with the search folder and advanced search option.
- General Settings: Date Filter, File Naming Policy, Custom Folder Name, and Skip Existing Exports.
- Advanced Controls: Attachments handling and delete duplication option.
- No data loss: The tool preserves the original mailbox structure, email formatting, attachments, metadata, internet headers, and folder hierarchy.
- Multiple License Options: Home, Administrator, Technician, and Enterprise.
- 100% Secure and Privacy-Focused: Your data remains completely private throughout the conversion process. The software performs all operations locally on your computer and does not store, upload, or share any of your OST files or mailbox data.
Simple Steps for Exporting OST Files to MSG
- Firstly, download and install the DRS Softech OST to MSG Converter Tool.

- Choose “Select Files” or “Select Folder” to add your OST files. Click Next. (Show File Path, Size).
.+ - In the preview panel, expand the hierarchy and double-tap to open the OST emails. If the preview fails, click on Open in Browser. You can use the Search Folder and the advanced search option. Select files/folders. Click Next.

- Click on Export in File Formats and choose MSG as the Saving Format.

- Apply general settings and advanced filters. Define the destination location and click Start Export.

Real-Life Scenario:
A finance company upgraded all employee computers to new systems. During the migration, one employee’s Outlook profile became inaccessible, but the old OST file was still available. The employee needed to retrieve several invoices and client approval emails as individual MSG files for auditing and legal records. Instead of rebuilding the Outlook profile or manually saving each email. The IT team used the DRS Softech OST Converter to export the required emails to MSG format without any data loss.
Conclusion
In this blog post, we discussed multiple methods to convert OST to MSG. The manual methods are only used for a few emails or when your Outlook profile is active. To convert bulk files, you can use the professional tool. It allows users to convert multiple or large OST files simultaneously with a guarantee of no data loss. It is tested by several experts and preserves the original email formatting. You can also download the demo version of this tool to convert 50 emails per folder.
Frequently Asked Questions
Ans. You can convert an OST file to MSG using Outlook’s Drag and Drop or Save As option if the OST file is connected to an active Outlook profile. For orphaned or large OST files, use a professional OST to MSG converter.
Ans. Yes. Professional OST conversion software can convert orphaned OST files to MSG without requiring Outlook or the original Exchange profile.
Ans. Yes. A reliable OST converter preserves email metadata, including sender and recipient details, subject, timestamps, attachments, internet headers, and formatting during conversion.
Ans. Yes. An advanced OST converter tool supports the conversion of large OST files while maintaining data integrity and mailbox structure.
Ans. By using the Date filter of DRS Softech OST File Converter, you can perform selective email conversion. Click on Date Filter and enter Start or End date.
Ans. Yes. The DRS Softech OST Converter performs the conversion locally on your computer. It does not upload, store, or share your mailbox data, ensuring complete privacy and security.
Ans. Yes. The software supports batch conversion, which allows administrators to convert multiple OST files into MSG format in a single operation.
Ans. Yes. If the OST file is orphaned or belongs to an inactive Outlook profile, a professional OST converter can still access and convert the mailbox without reconnecting the original account.
Ans. Yes. The DRS Softech OST Converter is designed to process large OST files, including files larger than 100 GB, while preserving email content, attachments, and folder hierarchy.