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How to Import MBOX to Office 365 Mailbox – Step by Step Guide

Published By Jamie Kaler 
Rollins Duke
Approved By Rollins Duke
Published On October 13th, 2023
Reading Time 7 Min Read

The process to import MBOX to Office 365 mailbox has many roadblocks. From understanding the requirements to choosing the appropriate method to get the job done, there are many things to take care of.

After all, upgrading to the Office 365 environment from desktop-based products naturally boosts productivity but if the migration is shabby, it will result in data loss. Thus, no productive results for the organization.

Through this how-to guide, we will explain step-by-step instructions that can help you import MBOX to Office 365 mailbox. As long as the steps are carried out systematically, MBOX to Office 365 migration will be free from errors and costs.

But before that, let us answer an important question – What kind of MBOX files can be migrated over? Is it limited to certain email clients, OS, or other things or are there no restrictions?

What Types of MBOX File Can Be Migrated?

Truthfully, there are no restrictions on the type of MBOX file for migration. As long as the MBOX file is not corrupted, then whether it comes from email clients (Mozilla Thunderbird, Apple Mail, etc.) or is downloaded from email services (Gmail, Backupify, etc.), all the data can be migrated over to Office 365 account.

In technical terms, you can import MBOX without an extension,MBOX, .mbx, .mbs files regardless of their origins.

Free Method to Import MBOX to Office 365

You can follow the step-by-step instructions given in the two stages below and import all your MBOX files conveniently.

Do note that the MBOX email client we chose here is Mozilla Thunderbird, since it is free, open source, and works seamlessly with MBOX file format.

Step 1: Connect Office 365 in Thunderbird

  1. Run Thunderbird on your computer to import MBOX to Office 365.
  2. For old Thunderbird users, go to Tools >> Account Settings.
  3. Select Add Mail Account from the Account Actions.

    import MBOX to Office 365

  4. Once you have the following screen, enter your name, email address (Office 365), and password for the email address. Once done, hit on Continue.

    name, email address

  5. The new screen shows default settings for IMAP and POP configuration. Here, choose the IMAP radio button. After that, click on Done.

    IMAP and POP

  6. A new window will appear for confirmation. Here, type the password and click on Sign in.

    type the password

  7. If the read and write access is not provided for IMAP configuration, the application may require you to request access from the Office 365 admin. Approve it if you have the Office 365 admin ID or notify the person if it’s with someone else.

    Office 365 admin

  8. Upon successful configuration of the Office 365 account, all its emails will start appearing on the Thunderbird page.

Step 2: Import MBOX to Office 365 Mailbox

  1. Firstly, go to the Tools menu and click on Add-ons and Themes from the list of available options.
  2. Then type ImportExportTools NG and click on the Search icon in the Search bar.
  3. In the new window, hit the Add to Thunderbird button corresponding to the relevant add-on.
  4. After that, click the Add button to finalize the add-on installation.
  5. Now, close and restart the Thunderbird email client to import MBOX to Office 365.
  6. Afterward, look for the Local Folders mailbox on the Thunderbird screen and right-click on it.
  7. Then select ImportExportTools NG >> Import MBOX File to Open Up the MBOX import window.

    Importexporttools NG

  8. After that, choose the Import One or More MBOX Files option and click on OK.

    Import One or More MBOX

  9. In the window that appears, select the MBOX file(s) that you want to import to Office 365. After that, click on Open.

    import MBOX to Office 365

  10. The files be imported under the Local Folder section. Now, open the folder, and select all the emails.
  11. Then, right-click and bring your cursor on Copy to >> [your Office 365 account] and proceed to select the folder in which you want to import MBOX to Office 365.

    Copy to

  12. Finally, all the data is successfully migrated.

Drawbacks of the Free Method

  • Lack of filters to weed out unwanted emails.
  • Cannot import MBOX files to different Microsoft 365 accounts at once.
  • You cannot connect the account if the access is not provided by the admin.
  • The emails are copied and not directly imported, so there may arise discrepancies in the metadata.

It is better to opt for a tried and tested approach like RecoveryTools MBOX to Office 365 migrator to import MBOX to Office 365.

Simplest Solution to Open MBOX Files in Office 365 Account

RecoveryTools MBOX Migrator is by far the best tool to get the job done in a hassle-free manner. The software comes with amazing and advanced filters, and it has been created with highly advanced algorithms, which makes it more powerful, easy to use, and the first choice of users. It can easily import MBOX files to Microsoft 365 accounts with a variety of features:

Important Tip: Make sure to install the free demo version of the software and test the entire migration beforehand. The demo only allows 25 emails per MBOX file to be migrated.

  • The software allows users to load MBOX files and folders using the Select Files and Select Folders options easily to import MBOX to Office 365.
  • This MBOX to Microsoft 365 migration tool comes with an advanced filter option, which allows users to import selective emails via Date Range, To, From, Subject, etc.
  • Also, users can easily upload single or multiple MBOX files in bulk at once without having file size limitations.
  • There is no need to do any extra import or export process to import MBOX to Office account because this tool can open MBOX directly in Office 365.
  • The MBOX to Office 365 migration tool allows users to map folders into different languages including English (Default), Spanish, Dutch, German, French, Finnish, Swedish, Norwegian, Italy, etc.
  • The Copy to Default Folder option allows users to move folders in the same source folder.

Steps to Import MBOX to Office 365

  • Step 1: Open MBOX to Office 365 migrator tool.
  • Step 2: Add MBOX files using Select Files/Folders.
  • Step 3: Choose Office 365 as a saving option.
  • Step 4: Put the login details of O365.
  • Step 5: Click on the Convert button to start the process.

Complete Working Steps to import MBOX to Microsoft 365

  1. Download and install the MBOX to Office 365 migration tool.

    MBOX to Office 365 Migrator

  2. Upload the single or multiple MBOX files using the Select Files and Select Folders option.

    Upload the single or multiple MBOX

  3. All the available data will appear and check the required folders and subfolders from here and click on the Next button to import MBOX to Office 365.

    required folders and subfolders

  4. Click on the Select Saving Option, scroll down, and choose the Office 365 option from the dropdown.

    Select Saving Option

  5. Select the Filter Options tab and enable the Use Advanced Setting for selective MBOX to Office migration.

    Filter Options

  6. Enable the Change Language option to map the folder as per your choice.

    Change Language

  7. Enter the email address of your Office 365 account.

    Office 365 account

  8. Then a window will appear and put the again email address and password and click on the Continue button.

     email address and password

  9. Import MBOX to Office 365 live process will start on the screen.

    Import MBOX to Office 365

Frequently Asked Questions

  • Is MBOX compatible with Outlook?

    No, Outlook doesn’t support MBOX files, it only supports PST, MSG, OST, and NST file formats.

  • What software can read MBOX files?

    You can use the RecoveryTools MBOX viewer, which allows users to open and read MBOX files for free.

  • How do I open a shared mailbox in Outlook 365?

    If you want to import a shared mailbox to Office 365, then visit the mentioned blog. Here you will get the complete information about the process.

  • Is this software allowing users to import emails to the User O365 account?

    Yes, you can easily import MBOX to the user’s Office 365 account, and if you have an admin account then enable the I Am Admin option.

Final Thoughts

It’s not easy to migrate email clients’ databases over to a SaaS solution like Office 365. Fortunately for MBOX users, there is a RecoveryTools MBOX to Office 365 migrator to get the job done. Whether it’s convenience or accuracy, this professional solution stands way above the free methods. All you need to do is take note of the instructions provided in the video to easily import MBOX to Office 365.