Mozilla Thunderbird mail users are migrating to Office 365 for reasons like security, scalability, availability, collaboration, and affordable subscription-based pricing.
However, migrating Thunderbird emails to
Office 365 or any other email client along with attachments is not an easy
task. Firstly, Office 365 doesn’t support MBOX file type that is used in Thunderbird
for storing mailboxes-comprising emails, attachments, contacts and calendars, etc.
So, migrating Thunderbird mailboxes to Office 365 would first require
converting all the data into a supported format such as Portable Storage Table
(PST) or EML.
There are several
methods available for migrating Thunderbird to Office 365 account. In this blog
post, we will discuss them in detail.
Methods to migrate Thunderbird mailboxes to Office 365
As mentioned before, there are several methods of
conversion. Let’s discuss those briefly below:
Method #1: Import EML Files to Office 365
Step 1:Save Thunderbird Email to Windows PC
First of all,
create a new folder on Desktop.
the Thunderbird application on the system.
that, open the message folder where the emails that need to be moved
from Thunderbird to MS Outlook are saved.
Then, select all
on the messages and select Save As option.
Then, Browse to
the desktop folder and save the emails there.
Step 2: Import EML to Outlook 365
the Outlook email application.
Then, go to
the folder in Outlook where the Thunderbird messages will be saved.
select Folder tab and select the New Folder option.
In the Create
New folder dialogue box, set a name for the new folder.
Next, click on
the OK button to migrate Thunderbird email to Office 365. Now, this
folder will be shown on the left panel of the email application.
Next, click on
the Folder to open its content on the center panel.
Finally, drag all
the messages from Desktop folder to this folder in Outlook and your
data will be migrated successfully.
Method #2: Forward as Attachments
Thunderbird on a Windows PC.
the messages that need to be imported from Thunderbird to Outlook account.
on them and select Forward as Attachment.
This will open a new
email window in which emails with be added as EML attachments.
Next, type in
an email ID to migrate Thunderbird to Outlook 365.
Then, click on
the Send button.
Finally, view the
Thunderbird emails on Office 365 Mail App.
transfer process by logging into the O365 and opening each email one at a time
through a browser in EML format.
Limitations of this
Migrates Limited Emails: The process to transfer Thunderbird emails to
Exchange Online is not meant to move complete email folder containing over 1000
emails. It can only export limited number of conversations.
Lengthy and Time-Consuming: It would take a lot of time to move each email,
one at a time, to desktop and then to Outlook. Forwarding hundreds of
Thunderbird messages to Outlook 365 with large attachment files may take a lot
Data Integrity Compromised: Often email formatting or SMTP header is changed
for some emails during transfer.
The best alternative: For migrating Thunderbird to Office 365
The above discussed methods to migrate Thunderbird
email to Office 365 would not be suitable for migrating a large amount of
emails, attachments, contacts, etc. It’s better to use a professional software that
specializes in exporting Thunderbird mailbox data to Office 365.
Stellar Converter for MBOX Technician is one of the most-preferred software tools widely used for migrating mailboxes from Thunderbird and other MBOX-based email clients to Office 365.
The trial version of the software lets you evaluate core functionality by way of scanning and preview of the converted emails, as follows:
On the software’s home screen, use the dropdown to select the source mail client to be converted to PST format
On the same screen, click on ‘Select File’ to convert a single MBOX file. If you wish to convert multiple MBOX files in a folder, then click on ‘Select Identity Folder’
Once the file is selected, click on ‘Convert’ to begin the scanning process
When the scan finishes, you can check the preview of all mailbox components
Click on the ‘Save’ button from the main menu to save the converted mails. You can save them to new or existing MS Outlook PST file, EML, MSG, RTF, PDF, HTML, as well as Office 365 file formats. Click on ‘Next’ after selecting an output format.
If you select Office 365, provide your login credentials and click on Next to proceed
Once the conversion is complete, you will be shown an appropriate message.
That’s it, you’re good to go.
Wrapping it up
Thunderbird uses MBOX file for storing
mailbox data, which is not supported by Office 365, so, you’d need to first
convert the MBOX file into a compatible format such as PST or EML. In this blog
post, we shared a few methods to help you migrate from Thunderbird mail client
to Office 365.
We outlined both manual and
software-based methods for converting MBOX to PST or EML, all of which work
fine from a technical standpoint, meaning, they do convert MBOX files to enable
migration of mailboxes to O365.
But, for all practical purposes—wherein high volume and variety of mailbox data is concerned—the software should be used. Why? Because as a business or an individual user you wouldn’t want to waste your time or get hassled performing the manual procedures while putting your mailbox data at risk of losing integrity. Using a specialized MBOX converter utility such as MBOX to Office 365 Converter by Stellar, automates the task with high precision, while minimizing the need for continual monitoring.
The software is available for free
trial which offers scanning and preview of the mailbox data. Once you’ve
ascertained its effectiveness, you can then make an informed decision. It’s
Eric Simson is an Email Platform Consultant and is associated with Stellar Data Recovery from last 6 years. He writes about the latest technology tips and provides custom solutions related to MS Outlook, MS Exchange Server, Office 365, and many other Email Clients & Servers.