How to Convert OST to MSG Files in Bulk

Written By Shivam Rathore
Updated on July 7th, 2025

Summary: Outlook OST files are a copy of the Exchange mailboxes stored on the system and are generally available offline. These files store all their data but lack flexibility and portability. This is where the need for another format with these properties arises, like MSG. So, to understand all about it and learn how to convert OST to MSG files, we will explore free solutions and an OST Conversion Tool.

Download Now Buynow

Why Export OST to MSG Files?

OST (Offline Storage Table) keeps offline mailbox emails and other items created by Outlook, O365 Exchange, and IMAP. It is bound to one Outlook profile and is hard to organize due to its large size. Best suited for internal syncs.

Whereas, a Microsoft Outlook message file is a single email message beneficial for backup, sharing, and archiving. It is quite easy to move and can be seamlessly managed because of its small size. Moreover, it has many other advantages over the OST file, such as:

Doesn’t require internet connectivity to be synced with the mail server at all times.
Ideal for business, legal, and backup, where tracking of emails individually is important.
The search and data storage process becomes fast and smooth, making it easier to handle projects and client emails.

Best Approaches to Convert OST to MSG Files

Though several manual methods are available, we will go with the two convenient solutions. Other than that, we will see a trusted professional tool for OST to MSG conversion. Using the manual method can be a little inconvenient and tricky, especially if you are a new user. So, follow the mentioned process carefully for the optimum results.

Manual Way to Transfer OST Files to MSG Format

The methods discussed here can be time-consuming and involve a risk of losses. Additionally, they only move emails and not other items in any way. So, if you only need to move emails for free, the steps are:

#Using Drag & Drop to Convert OST to MSG Files

Launch Outlook and ensure it is connected to the Exchange server so that you have OST files.
Yet, if you don’t have them, then first, open OST file in Outlook.
Further, from the OST folder, select all emails (Ctrl + A) or the selective ones as per your choice.
Open File Explorer and create a destination folder for your OST messages.
Finally, drag and drop the emails from Outlook into the folder created within Explorer.

#Save OST File to MSG

Choose your OST emails to move, right-click, and pick Save As.
Then, opt for the (.msg) file type, select a folder location, and hit Save.

That’s how you can freely move emails from OST to MSG file.

Tool-Based Method to Convert OST to MSG Files in Bulk

When it comes to saving OST emails securely, accurately, and without hassle, the OST Conversion Tool is the perfect fit. This doesn’t require a specific Outlook installation or lengthy procedures. Instead, it enables you to save OST files to Outlook MSG or convert OST to EML and more formats while maintaining data integrity and structure intact. Moreover, it even offers advanced filter capabilities.

The steps you need to follow to use the software are:

Download and run the given utility on Windows or Mac as an admin.
Then, add your Outlook OSTs into it and click on Next to proceed.
Preview entire folders and attachments within and select those to move.
Further, with Next, proceed to pick the required saving format, i.e., (.msg).
At last, specifying the filters and choosing a destination, click Convert.

Doesn’t this seem quite easy and quick? It is because with this, you can bulk migrate data in no time. Also, it has a trial version for your ease of understanding, and if needed, you can even book a demo with our tech consultant.

User Response:

“Being a legal IT administrator, I often require individual MSG files from old OST backups for compliance and case documentation. This tool made the bulk export seamless and retained the folder structure, which was crucial for search. It saved me hours of manual work, and so I would highly recommend it for use.”

Conclusion

It is quite easy to convert OST to MSG files, whether you do it manually or use a professional tool. For a few emails and with sustained technical knowledge, the manual works fine. But for large data volumes, bulk migration, and entire OST mailbox conversion, including contacts, calendars, etc., use the dedicated tool.

Frequently Asked Questions

Q1. How do I change an OST file into an MSG file in Windows?

Ans. To change OST into MSG on any version of the Windows OS, say the latest Windows 11 to the earlier 10, 8.1, 8, 7, XP, etc. Use the OST to MSG Converter Tool as it is highly compatible, secure, and easy to use.

Q2. How to convert OST to MSG files with attachments?

Ans. Just go through these steps to convert OST to MSG with the attachments:
Download and then start the OST to MSG Conversion Tool.
Next, upload and preview the OST files for verification.
Select the MSG format, and then proceed by clicking Next.
Finally, hit Convert to finish the file with attachment conversion.

About The Author:

Shivam Rathore

Meet Shivam, an experienced SEO executive and content strategist. He combines creativity with strategy to craft engaging content that connects with audiences and supports brand goals. With strong expertise in digital marketing and content planning, Shivam helps businesses thrive online.