Home » Blog » Data Migration » How to Import MBOX to Microsoft 365 – 3 Simple Methods

How to Import MBOX to Microsoft 365 – 3 Simple Methods

how to import mbox to office 365 microsoft

Nilesh Kumar | Modified: December 28, 2021 | Data Migration, Office 365 | 6 Minutes Reading

Know how to import MBOX to Office 365 using 2 free manual methods. If you seek professional help, there is an automated tool included as well.

Cloud is the future. It is powerful, cost-effective, and will continue to grow in the future. Whether it’s enterprise or self-employed individuals, everyone is more or less shifting to cloud applications to better manage their work.

The same holds true for desktop email client users. Many have already shifted their mailboxes to cloud applications like Microsoft 365 that allows them to work anytime, anywhere. In this article, we are focusing on specific user groups who wish to move their MBOX files to Office 365 accounts.

The MBOX files can be of any origin

  • Associated with email clients like Mozilla Thunderbird, Entourage, Apple Mail, The Bat, etc.
  • Downloaded from email apps like Gmail.
  • Backup files created through Backupify, MozBackup, etc.
  • Old archive mailboxes of different types – .mbox, .mbx, .mbs, MBOX without extension.

Regardless of its origin, as long as you have a healthy MBOX file, you can easily import it in Microsoft 365 after reading this article.

Without further ado, let us start with the manual methods first.

Free Methods to Import MBOX to Office 365

We will discuss two free methods here:

  1. Configure Office 365 account in MBOX email client – Here, we will configure Microsoft 365 in Thunderbird and copy the emails inside MBOX file into Office 365 mailbox.
  2. Move emails to Outlook & use Azure AzCopy Tool to Upload it to O365 – Here, we will move the mailbox data to Outlook and create a PST file. Then, upload this newly-created file to Microsoft 365 account.

Then, we will discuss the most popular automated professional solution as an alternate method.

#1 Configure Office 365 account in MBOX email client

Let us use IMAP during account configuration as most free email clients lack Exchange.

Part 1:

  • Free download Thunderbird email client from the Mozilla website.
  • Install this email client and launch it.
  • When creating a new account, choose to skip and use existing email.
  • Enter your name, Microsoft 365 email address and password in the Mail Account Setup Wizard.

enter name and mail id

  • Click Configure Manually and Enter the following settings:
    • Incoming: IMAP, server name – outlook.office365.com, port – 993, SSL – SSL/TLS, Oauth2 authentication, username – your O365 email id
    • Outgoing: SMTP, server name – smtp.office365.com, port – 587, SSL – STARTTLS, Oauth2 authentication, username – your O365 email id

server settings

  • Click Done and Authenticate your account.

Part 2:

  • Now, import MBOX to Thunderbird using ImportExportTools NG add-on.
  • With the email client still open, tap the Alt key.
  • Go to Tools menu and select Add-ons
  • Search for ImportExportTools in the search bar.
  • Click on +Add button >> Add corresponding to the ImportExportTools NG.

add button

  • Restart the email client.
  • Right-Click on Local Folders >> ImportExportTools NG >> Import MBOX File

importexporttools ng

  • Click Ok and select the MBOX file you want to import in Microsoft 365, then click Open.
  • The file is now added and emails are available in the email client.

Part 3:

  • Select all the MBOX emails (Ctrl+A) and right-click.
  • Choose Copy to >> your office 365 account.

copy to office 365

  • This will copy all the emails from MBOX to Office 365 mailbox. Check the Microsoft 365 account on a browser to confirm that all the files are there.

#2 Move emails to Outlook & use Azure AzCopy Tool to Upload it to O365

The basic idea behind this free method to import MBOX to Office 365 is to use an MBOX supporting email client (Thunderbird) to facilitate importing MBOX emails to Outlook. Then, using the Azure AzCopy Tool to upload the emails to Office 365.

The steps are as follows:

Part 1:

  • Install Thunderbird from Mozilla website.
  • Launch it but do not configure any account.
  • Only Local Folders will be present in the mailbox section.

Part 2:

  • Exactly same as the Part 2 in the #1 Method.
  • You now have all the MBOX emails inside the Local Folders.

Part 3:

  • Select all the emails and drag and drop them into a folder on your computer to create EML files.
  • Open MS Outlook and drag and drop the EML files into a mailbox folder in Outlook.
  • Now, got o File menu and click Open & Export >> Import/Export
  • Choose Export to a .pst file
  • Select the folder containing dragged and dropped emails for export.
  • Give a destination location for the PST files.
  • Finally, click on Finish button.

Part 4:

Simply perform the steps to import PST to Office 365.

Limitations of the Manual Methods

  • Requires installation and configuration of multiple email clients
  • Must have technical expertise to use O365 of other applications
  • Does not guarantee to retain data integrity
  • Steps are time-consuming and will lead to a lot of complexity if there are more than one MBOX files

Professional Way to Import MBOX Files to Office 365

If the complex and time-consuming manual methods are not your cup of tea, then how about giving this professional tool a try – MBOX to Office 365 Migrator.

Free Download Purchase Now

Benefits of using Professional MBOX to Microsoft 365 Tool:

  • Allows to batch import multiple MBOX files into O365 account(s) at once
  • Allows uploading files to more than 1 account at a time through impersonation.
  • Date-range filter is available to migrate selective emails
  • Option to maintain folder hierarchy/structure

How to Import MBOX to Office 365 Using This Tool

Complete Guide

1. Run MBOX to Office 365 Migrator on your Windows system and click Add Files button.

start mbox to office 365 migrator

2. Add MBOX file(s) from the system into the software.

3. Choose to Maintain Folder Hierarchy and click OK.

maintain hierarchy

4. Select one of the following methods:

  • With impersonation (How to apply)- Requires admin id. Feasible if you want to import MBOX files to several Office 365 accounts.

with impersonation

  • Without impersonation

without impersonation

5. Input and Login to validate the account and map the added MBOX file(s) to corresponding Office 365 id.

6. Click Set button to apply Date-range filter.

apply filters

7. Click on Export to start importing MBOX files to Microsoft 365 account.

export mbox to O365

8. Save the progress report once the process completes for future use.

Concluding Thoughts

Microsoft 365 is the new trend. When moving to the cloud, one will always consider O365 among the valid options. And if confirmed, the task of importing local mailboxes to M365 becomes an important one. We have 3 methods here to get you through the MBOX to Office 365 process in a seamless manner. Well, some methods are more seamless than others. Anyways, you can opt for any of the given ways to either import MBOX to Office 365 for free or use a professional tool for more ease. We will recommend the professional tool as it overshadows all the limitations of the manual methods and provides you with the capability to upload multiple files in one go.

Some Common Queries

How can I Import MBOX to Microsoft 365?

Steps to import MBOX to Microsoft 365:

  • Step 1: Run MBOX to Microsoft 365 Migrator.
  • Step 2: Select MBOX files to import.
  • Step 3: Choose with/without impersonation.
  • Step 4: Input Microsoft 365 creds to login.
  • Step 5: Set filters & import MBOX to Microsoft 365.