Export Office 365 Emails to MBOX: Best Automated Methods
-
Written By
Aradhya Jain -
Approved By
Shivam Rathore -
Updated on
May 29th, 2026 - Read Time
6 minutes
User Query: I’m switching from Office 365 to Thunderbird and need to export Office 365 to MBOX format. Is there an easy way to do this without losing attachments or folders?
Introduction: Office 365 does not give you a direct “Export to MBOX” button. The platform saves and stores emails in the cloud. Besides that, MBOX is a completely different format used by desktop clients like Thunderbird, Apple Mail, and others. But that does not mean it is impossible. There are two practical methods to export Office 365 to MBOX. One is free (using Mozilla Thunderbird), and the other uses a professional DRS Softech Office 365 Backup Tool when you have a large mailbox. This blog explains each method in detail without any technical knowledge.
Why Do Users Need to Convert Microsoft 365 to MBOX?
- MBOX is supported by popular email clients like Mozilla Thunderbird and Apple Mail.
- Users want to create a secure backup of Office 365 emails.
- Many organizations migrate from Microsoft 365 to open-source email platforms.
- MBOX files are easy to archive and store locally.
- Moreover, users want offline access to their important emails.
Can You Directly Save Office 365 emails as MBOX?
The simple answer is NO. Microsoft Office 365 does not offer a built-in feature to export mailboxes directly into MBOX format. Instead, Microsoft allows users to export mailbox data in PST format using the Outlook desktop application.
Manual Method to Export Office 365 Emails to MBOX
Users who do not want to use third-party software can manually export Office 365 emails to MBOX format with the help of Mozilla Thunderbird. This process takes some time, but it works for small mailbox data.
Step 01: Configure Office 365 Account in Thunderbird
- First, install and open Mozilla Thunderbird on your computer.
- Now, go to Account Settings.
- Click on Account Actions and choose Add Mail Account.
- Enter your Office 365 email address and password. Click on Continue.
Step 02: Create a Local Folder
- Then, right-click on the folder panel.
- After that, select New Folder.
- Create a local folder where you want to save the emails.
Step 03: Move Office 365 Emails
Now, select the emails or folders from your Office 365 account and move or copy them into the newly created local folder inside Thunderbird. Wait until all emails are synced properly.
Step 04: Export Emails as MBOX
- Install the ImportExportTools NG add-on in Thunderbird.
- Right-click on the local folder you created.
- Choose ImportExportTools NG.
- Afterwards, click on Export Folder.
- In the end, select the destination location on your system.
Limitations of the Manual Method
- The process becomes very slow for large Office 365 mailboxes.
- Bulk mailbox export is not possible manually.
- There is a risk of missing attachments or email properties.
- Users need enough local storage space for the export process.
- The steps may be confusing for non-technical users.
- Additionally, Thunderbird add-ons may sometimes fail during export.
Professional Tool to Export Office 365 Emails to MBOX
For a bulk or large Office 365 email migration, you can use the reliable DRS Softech Microsoft 365 Backup Tool. This tool allows users to export a single or multiple Office 365 emails at once with no data loss. It maintains the original email formatting, structure, and metadata during the process. You can easily migrate Office 365 to Gmail and other email clients. With its simple interface, every user can easily perform it (Technical and Non-Technical). Furthermore, it is highly compatible with all Windows and Mac versions.
Steps for Exporting Office 365 into MBOX File:
- Download and install the DRS Softech Office 365 Email Backup Tool.
- Now, enter your Office 365 Email Address and Password to Sign In.
- Import users via CSV or Add User Automatically. Select Primary Mailbox, Online Archive, or Public Folder. Hit Next.
- Then, preview and select the Office 365 emails to export. Click Next.
- Further, choose the MBOX as the Saving Format from the given list.
- Lastly, apply advanced features and filters as per your needs. Press Convert.
Real-Life Scenario
Sarah, an operations manager at a logistics firm, needed to move four years of Office 365 emails to Thunderbird before a company-wide platform switch. She tried the manual Thunderbird method first; it worked fine for her inbox, but crashed repeatedly on a shared folder with 12,000+ emails. Attachments went missing, syncs dropped halfway through, and she was losing days on it.
Then, she used the DRS Softech Office 365 Backup Tool instead. The entire migration finished in under two hours, attachments intact, folder structure preserved, zero missing emails. Also, you can migrate emails from Office 365 to Zoho Mail and other email clients.
Conclusion
In this technical blog post, we explored several methods to export Office 365 emails to MBOX. The manual method is used to export a small number of Office 365 emails by using Thunderbird. However, it has several limitations. That’s why it’s best to use the professional tool. It supports bulk processing with different advanced features. In addition, you can free version of this tool to understand its features and performance.
Frequently Asked Questions
Ans. The safest way is to use a professional Office 365 backup tool that supports Modern Authentication (OAuth 2.0). This means your credentials are never stored or shared.
Ans. Yes, Both the manual Thunderbird method and professional tools like DRS Softech Office 365 Backup Tool retain email attachments during the export. A dedicated tool is more reliable when attachment preservation is a priority.
Ans. Manual methods simply do not scale. An automated tool handles bulk mailbox exports in one session, applies date-range filters, skips duplicate emails, and generates a completion log — saving hours of work and eliminating human error.
Ans. Yes, DRS Softech Office 365 Backup Tool is built specifically for enterprise-level mailbox sizes. They use secure login methods, handle large data volumes without crashing, and keep the original folder hierarchy and metadata completely intact throughout the export.
Ans. Technician editions are designed for IT professionals and MSPs who manage email migrations for multiple clients. These editions allow bulk processing across several Office 365 accounts without needing separate licenses for each one, making client-based migrations far more efficient and cost-effective.
Ans. The best tool to export Office 365 emails to MBOX is the DRS Softech Office 365 Backup Tool. It supports both single and bulk mailbox exports, keeps attachments and folder structure fully intact, and works on Windows and Mac.
