Method To Migrate Thunderbird MBOX File To Office 365

Thunderbird is a free and open source email client developed by the Mozilla foundation. It renders as email client, news client, RSS and chat client services to the users. It supports Linux, windows and Mac OS systems. Though it is a free and open source platform it mostly used by the small organization or for personal use. When it is used by small organization and with the change of time they moves to another email platform like Outlook 365 for safe and secure information exchange than they need to migrate their Thunderbird Mail data to Office 365.

In this page we would be discussing about how the Thunderbird files can be imported to Office 365 account. Various methods of conversion and affect of the migration using that particular method.

Related Software: If User want to Convert OLM Files to Gmail account. Click Here


Method To Export Thunderbird Mailbox To Office 365 Account

Step1: By Using IMAP Protocol

Step2: By Importing EML Files To Office 365

Step3: By Using Automated Third Party Tool


It allows the user for synchronization in 2-way between the email client used by you with the other online mail account. It is integrated with the facility to access the one mail account in multiple mail clients. Follow the below listed steps for conversion of Thunderbird file to Office 365 using IMAP:

• By using IMAP configure you Gmail account in Thunderbird

• Now Create New folder in Gmail and Select and Move the messages to be Exported

• Now you will able to see messages to be Exported to your mail account

• Now by using IMAP & POP3 configure to Office 365 using the same Gmail account

• The data Exported will be stored in PST format in Outlook.

Limitations: This method is quit lengthy and time consuming. This manual method can only transfer some of the mails and there are chances of data loss while using this manual process.


This process mainly completes the exports in two phases.

  1. Save the Thunderbird messages in Window PC.
  2. Import EML file to MS Outlook.
1. Save the Thunderbird Messages into Windows PC

a. Create New folder on Desktop

b. Run Thunderbird and Select the Messages which are to be Exported

c. Right click on the Selected files and Select save as option

d. Then go to Desktop then to the New folder created and click on save.

2. Import EML files to MS Outlook

a. Run MS Outlook application

b. Select/create New folder for Exporting the Thunderbird files

c. Now move the files from the Desktop folder to the above selected folder in Outlook.

Limitations: This method is not safe for migration of important files as there are chances of data loss during the conversion and it is lengthy, time consuming and less secure also. This method is applicable with Outlook version 2010 and its older version.


There is an easy, short and secure way by which the user can transfer his MBOX file of Thunderbird email to Office 365 (PST format). Professional always go for third party tool rather than migrating their files through manual process as manually there is no security of data and there are chances of data loss but by using third party tool they don’t have to face any such problem and migrate the files efficiently.

The one most reliable tool is MBOX to OFFICE 365 converter. It is best for the large organizations that have huge data of mail as this tool effectively transfer the bulky and large sized file without any data loss and maintaining the hierarchy of data. Some of the various features and facility that a user gets using MBOX to Office 365 converter are:

Key Features Of MBOX To PST Converter
  • Instantly Convert MBOX file to Office 365 File format in just few Clicks
  • Facility to Save MBOX file to PST, EML, MSG, EMLX, HTML platforms other than Office 365 Platform
  • Show Preview of Convertible emails before Saving
  • Supports 17+ MBOX-based email clients’ for conversion such as thunderbird, Eudora, Seamonkey, Spicebird, Mulberry, etc.
  • No File Size Limit for conversion
  • Compatible with All the Latest and older version of MS Outlook
  • Use Free Trial Version and Save up to 30 Emails free of cost.
  • 24×7 hours Customer consultant service

Steps to Convert Thunderbird MBOX file to Office 365 Account

Step1: Install and Run MBOX to Office 365 Migrator Software

Step2: Click on Browse button to Select the Thunderbird Mailbox MBOX Folder/File

How to Export Thunderbird Mailbox data to Outlook PST

Note: You can Select a Complete Folder or Select Manually the MBOX File

Step3: After Selecting the File/Folder Press OK

Import Thunderbird emails to Outlook PST

Step4: After Scanning the MBOX file user can See Preview of Emails

Migrate Mailboxes from Thunderbird to MS Outlook

Step5: Now Click on Office 365 button in tool bar at top and you get a popup box in which you will get the facility to migrate your MBOX files to Office 365 and Exchange Server. Click on Office 365 Entre your Email and Password and Click on Export Your files will be Exported to Office 365 platform.

Thunderbird to MS Outlook Converter tool

Automated Method

Migration from one email client to another email client in today era of competition and advancement has become compulsory for the user and it’s very complicated task for the users. So the expertise are of the opinion that the user must always go for the third party tool for migration as it does not have the chance of data loss and maintains the hierarchy of data.

It’s better to go for third party tool for migration rather than manual method as manual method requires technical knowledge for user and it’s not effective in complete migration of the file. It means that there are chances of data loss during the conversion. So go for an effective, efficient, cost effective, secure, and best third party tool such as Import MBOX files to Office 365 account .

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