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Today, numerous users opt for the desktop iteration of MS Office, accessible through the Office 365/Microsoft 365 subscription model. Differing from the standalone Office software, this version operates on a subscription basis rather than a one-time purchase. Nevertheless, its features and functionalities closely mirror those of the most recent MS Office suite. Like other Office applications, MS Outlook is an integral component of this suite. The appeal of Outlook Microsoft 365 has grown significantly, thanks to the widespread adoption of Office 365/Microsoft 365. Following their Office 365 subscription, many users who were previously using email clients like Thunderbird are migrating to Outlook Microsoft 365.

Are you seeking a reliable and user-friendly solution to access your MBOX emails within Microsoft 365?

Stop looking now!

We’ve established this blog with the aim of assisting you in gaining a comprehensive understanding of the process for importing MBOX files into Microsoft 365.

For those unfamiliar with Microsoft 365 Outlook, it’s the Outlook application included as part of your Microsoft 365 subscription.

Now, let’s return to the primary subject at hand.

MBOX serves as a file format widely employed by various email clients, including Mozilla Thunderbird, Eudora, Apple Mail, MS Outlook, PowerMail, among others. However, if you need to utilize this data within Microsoft 365, it necessitates either converting it to the PST format or directly importing it into Microsoft 365.

Instant Solution

Try automated tool Kernel MBOX to Office 365, to migrate single/multiple files directly from MBOX/MBX/MBS to Office 365 in a single attempt.

Need to Import MBOX to Microsoft 365

Microsoft 365’s Outlook, akin to its predecessors, empowers users to efficiently manage personal data such as emails, contacts, calendars, tasks, and journals.

Microsoft 365 Outlook is an integral component of the MS Office Suite. Those who acquire MS Office are provided with a professional email client as part of the package. In most cases, importing MBOX files into Microsoft 365 is unnecessary, unless you encounter difficulties with your MBOX email client. Nevertheless, it’s important to note that Outlook Office 365 offers enhanced features and capabilities compared to open-source email clients such as Mozilla Thunderbird, which relies on the MBOX format. Additionally, Outlook seamlessly integrates with Microsoft platforms, including MS Exchange Server and Microsoft 365.

Read Also: When transitioning from an MBOX email client to Outlook Microsoft 365, it’s necessary to transfer your MBOX emails into Outlook.

How to Import MBOX to Microsoft 365?

The only manual method to import MBOX emails to Outlook Microsoft 365 is by converting it to a PST mailbox, and for that, you can refer to free methods to convert MBOX to PST. For instance, if you possess both a Thunderbird account and MS Outlook installed on your computer, you have the capability to convert an MBOX file into a PST format. Here’s the step-by-step process:

  1. Launch Mozilla Thunderbird and choose the folder you wish to transfer.
  2. Highlight all the emails in that folder by pressing Ctrl + A.
  3. Next, select the desired emails, then perform a right-click and choose “Save As” followed by “File.”
  4. Please store the file in a designated location.
  5. Save the file, then exit Mozilla Thunderbird and launch MS Outlook.
  6. “Generate a fresh folder, then relocate the saved file by dragging it into this newly created directory.”

Therefore, MBOX emails are stored within a PST mailbox.
Importing MBOX files into Office 365 using manual methods can be overly complex, and these approaches may not be universally applicable to all MBOX clients. Additionally, they are limited to importing emails only. Therefore, opting for a third-party solution like Kernel MBOX to Office 365 is advisable, as it offers a swift and efficient means of migrating MBOX mailboxes to Microsoft 365 Outlook.

Drawbacks of Importing MBOX Into Office 365 using Manual Method

We are aware that the manual approach can bring MBOX files into Microsoft 365 mailboxes; nevertheless, it comes with various disadvantages.

  • Multiple applications must be installed to migrate MBOX files from multiple machines to a single Office 365 account, resulting in a time-consuming process.
  • With this approach, migrating mailbox items like contacts, calendars, tasks, and numerous other elements is not feasible.
  • Performing the process necessitates a strong grasp of technical knowledge and expertise.
  • There is no assurance of flawless outcomes.
Kernel MBOX to Office 365

Crafted using cutting-edge algorithms, Kernel MBOX to Office 365 empowers users to effortlessly migrate data from over 20 email clients to Microsoft 365. This process is both swift and hassle-free. Additionally, its intelligent filtering capabilities enable users to selectively import data that aligns with their specific needs. To gain a deeper understanding of this tool, let’s delve into its operational workflow.

  1. Install the software and launch it on your system.
  2. On the software’s main screen, select the “File” option located in the upper-left corner.Select MBOX file
  3. Include the particular MBOX file directory into the software and then select the “Finish” option.
    Add the specific MBOX file
    Note: You also have the option to choose multiple MBOX files individually.
  4. You have the option to view the folders that encompass the file. Simply click on any folder to preview its contents.Preview of MBOX files and folder
  5. To save as a PST file, press the Save button, choose the PST file option (for MS Outlook), and then proceed by clicking Next.
    Select PST as a file saving option
    Note: To store data in your Microsoft 365 mailbox, opt for Office 365 from the provided options, then proceed by clicking the “Next” button.
  6. Please customize the file filters to align with your specific criteria, including item type, date, sender, recipient, and more. Afterward, proceed by clicking the “Next” button.Apply filter option
  7. Offer the choice to split PST files as needed. Proceed by clicking “Next.”
    Provide PST file splitting option
    Note: In the next step, please furnish your Microsoft 365 login credentials and then proceed to click on the “Finish” button if you’re saving within the Microsoft 365 platform.
  8. Select Office 365 as a saving option

You can save the MBOX file as a PST file or directly to your Microsoft 365 account. Afterward, you can import the PST file into Outlook Office 365.


Transferring MBOX data into Microsoft 365 Outlook may appear overwhelming for newcomers, particularly when utilizing manual methods that can be intricate and less dependable. This article explores the swift import of MBOX files into Microsoft 365 Outlook through both manual procedures and an automated solution, Kernel MBOX to Office 365.

Kernel MBOX to Office 365