Free Methods to Import MBOX to Office 365 on Mac & Windows

What Happens If You Migrate MBOX to Office 365?

Unlike the usual reason for switching over to a cloud platform, there are many other essential factors:

• Consolidation of mailboxes from several email clients into one common Office 365 account.
• Archive of MBOX exports from Google Takeout, Postbox, etc., into a professional Microsoft space.
• Change from open-source email clients to enterprise-level Office 365 solutions with no downtime.
• Ensures compliance and high-end security for the data by centralizing the communication.
• MBOX to Office 365 migration even provides support for multiple languages, global accessibility, and advanced features.

So, with so many benefits and advantages, it is ideal to make a switch and proceed with work on a new platform.

Tech Guide 2025: Smartly Import MBOX to Office 365

Though there are various solutions available online, it is necessary to utilize the relevant ones. This section explains the best manual solutions as well as an automatic tool for swift and fast migrations.

Cost-Free Import MBOX File to Office 365

We will discuss the three free solutions available for this MBOX file import. It includes one each for Mac and Windows OS, and one for both. Follow the step-by-step detailed guide as stated below:

Way 1: MBOX Transfer Manually with Mac Mail + Mac Outlook

This method can only be performed on Mac systems, and you need both applications on the same system. The steps are:

1. Open Mac Mail → and upload MBOX, if you don’t already have it.
• Click Tools, then Import Mailboxes >> pick MBOX and press Continue.
• All the selected MBOX files appear in the Inbox.
2. Next, set up and configure the Mac Outlook account with Office 365.
• In Outlook for Mac, expand Tools and open Accounts.
• Then, press Add Account and complete syncing Office 365.
3. Finally, drag and drop emails from the Apple Mail folder to the Outlook 365 mailbox.

Way 2: Import MBOX to Office 365 Using Outlook PST Format

This method can only be performed on the Windows OS, and you need to first convert MBOX to PST. Later, upload the MBOX file as an Outlook PST to an MS O365 mailbox of choice. Follow these steps:

1. Firstly, you need to convert the MBOX file into the PST format using a third-party tool. Like, SysInfo MBOX to PST Converter Tool.

(It is suggested because the manual conversion is too tricky and risky.)

2. Now, ready and organize PST to import MBOX in Outlook 365. Ensure to have global admin access for Office 365.
3. Further, download, install, and run the Azure AzCopy Storage Tool. Copy the SAS URL too.
4. Next, use this tool to copy PST files to a secure Azure storage with the command:

   azcopy.exe /Source:”C:\PSTfiles”/Dest:<AzureStorageURL> /V:”C:\Log\log.txt”

5. Afterward, create a PST Mapping CSV file to define which PST belongs to which user mailbox. Example:

   ServerWorkload, PSTFilePath, FileName, O365Mailbox, IsArchive, TargetRootFolder, ContentCodePage MSExchange, C:\xxx, sample.pst, user@mailbox.com, FALSE, xxx, 1252

6. Open the MS Office 365 Compliance Center and navigate to the Data Lifecycle Management option.
7. Here, you can import MBOX to Office 365 by selecting Import >> PST Upload >> Access to Azure storage.
8. Finally, submit the mapping file, click Save, and validate the import process.
9. Press Import to run the Network Upload migration job and monitor the progress.

Way 3: Migrate MBOX to Office 365 Using Thunderbird + IMAP

This method can be used on both operating systems. The steps are defined as:

1. Begin with the Mozilla Thunderbird installation. Run it and upload MBOX.
• Utilize add-on: ImportExportTools NG for MBOX access.
• These will appear in Thunderbird’s Local Folder.
2. Later, use IMAP and add the target Office 365 account in Thunderbird.
3. Lastly, use drag and drop to move emails from the MBOX folder into Office 365.

Well, these were the specific freeways available to import MBOX file to Office 365. However, the free manual solutions always have some shortfalls.

Why Manual Methods Don’t Work?

• Attachments and formatting aren’t preserved accurately in these ways.
• Not possible to import contacts and calendars in the 1st and 3rd ways.
• Also, there are no options for batch data transfers in the same.
• The methods are highly risky, lengthy, and difficult, requiring expertise.
• You need to have proper internet connectivity all the time for import.

Effortless Approach to Import MBOX to Office 365

Since manual methods don’t align well in terms of speed, accuracy, security, and batch conversions. We introduce you to the SysInfo MBOX to Office 365 Migration Tool, which makes the import seamless for all kinds of users. This tool has an easy-to-use GUI, suitable for all OS, and supports adding huge data volumes at once for migration in no time.

With this versatile utility with advanced capabilities, you can convert MBOX to MSG, CSV, etc., and any of the email clients. It has a demo version for your evaluation and a few free migrations.

Step-by-Step Guide to Import MBOX in Outlook 365

1. Launch MBOX to Office 365 Migrator and >> continue by Next.
2. Then, access MBOX files of any chosen client from PC and add them.
3. Click Next, and all the scanned files appear in a tree hierarchy.
4. Further, preview, assess them, and select >> click Next.
5. Choose Office 365 from the list and Sign in the modern way.
6. At last, pick your mailbox, filters, and click on Convert.

Wasn’t this way easier than all three of the given manual methods? You don’t need any special skills or other applications with this software.

Conclusion

While the manual methods come free, they have limitations in terms of volume, reliability, and complexity. For one-time import MBOX to Office 365 with less data, Thunderbird, Apple Mail, or even Outlook methods are feasible. But for bulk and business-level imports, using professional tools like the one above ensures accuracy, security, and full control. So, make your decision for the import wisely with the right method.

FAQ

About The Author:

Suman Rawat

Suman Rawat is a technical content writer and expert in the fields of email migration, data recovery, and email backup. Her passion for helping people has led her to resolve many user queries related to data conversion and cloud backup.