1. My personal experience is that vanilla Thunderbird does not behave at all with Office365. Folders are often a nightmare, the whole inbox is periodically re-downloaded for no reason, opening emails hangs for a while at random, and one of the worst: when re-opening an email I opened couple of minutes ago needs to re-download the whole thing.
2. Setting up an Exchange account in Thunderbird is slightly different to other email clients, as you have to setup the account manually. If this is the first email account setup on Thunderbird it will automatically open up a welcome window, where you will need to select Skip this and use my existing email.

• Thunderbird Office 365 Exchange Login
• Thunderbird Exchange Calendar Office 365

Thunderbird does NOT support Microsoft's proprietary protocols to access Exchange servers or Office 365. If your administrator does not allow IMAP access, then you won't be able to use Thunderbird with your account. Do you have any IMAP settings for the server? Export from Thunderbird to Office 365 to read emails through a browser on any mobile or tablet device. Get unlimited Office applications like Word, Excel, Access, Skype, Exchange server etc. Methods to Migrate Thunderbird Email To Office 365.

Email migration is quite a challenging task. Different organizations use different strategies to perform Thunderbird to Office 365 migration. Any organization that undertakes it typically needs to export thousands of bulky mailboxes from one platform to another. In addition to the hurdles and risks involved, format incompatibilities between the source and destination platform play a crucial factor. If your organization wishes to export MBOX to office 365, this post is for you.

In this article, we are going to discuss manual methods to migrate MBOX to office 365. But before moving towards on different solutions to import the MBOX file to Office 365 account, let us shortly discuss the major reasons for this migration process.

Why you wish to migrate Thunderbird to Office 365?

Following are some of the reasons for moving from Thunderbird to Microsoft cloud services with O365:

• Office 365 provides added features of data share, storage, communication, and collaboration.
• It also added security and data storage benefits with O365 cloud servers.
• To get unlimited Office applications like Word, Excel, Access, Skype, Exchange server, etc.
• It provides all the Office suite applications including Exchange online server and Office 365 Mail App at low cost.
• This enables businesses to import or migrate Thunderbird emails to office 365.

Methods to Migrate Thunderbird Email To Office 365

Thunderbird Office 365 Exchange Login

Following are some of the manual methods for transferring mailbox information to the Microsoft cloud servers with Office 365:

Method 1. Import MBOX Files to Office 365

The manual procedure to migrate Thunderbird MBOX file to Office 365 involves two phases, viz. Save Thunderbird Email to Windows PC and then Import EML to Office 365. Here are the broad steps to cover these phases:

Step 1: Save Thunderbird Email to Windows PC

Thunderbird Exchange Calendar Office 365

• First, create a new folder in Desktop.
• Next, launch the Thunderbird application on the system.
• After that, open the message folder where you need to move emails from Thunderbird to MS Outlook are saved.
• Then, select all the messages using the Ctrl+A key.
• Now, Right-click on the messages and select Save As option.
• Finally, Browse to the desktop folder land save the emails there.

Step 2: Import EML to Office 365

• First, launch the Outlook email application.
• Now, go to the folder in Outlook where the Thunderbird messages will be saved.
• Or, select the Folder tab and select the New Folder option.
• In the Create New folder dialogue box, set a name for the new folder.
• After that, click on the OK button to migrate Thunderbird email to Office 365.
• Now, this folder will see 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 the Desktop folder to this folder in Outlook.

Method 2. Forward As Attachments

• Open the Mozilla Thunderbird on a Windows PC.
• Then, select the messages that need to be imported from Thunderbird to the O365 account.
• After that, right-click on them and select Forward as Attachment.
• You will encounter a new email window in which emails with be added as EML attachments.
• Next, type in an email ID to migrate MBOX to Office 365.
• Then, click on the Send button.
• When the process is finished, view the Thunderbird emails on Office 365 Mail App.

Verify the migrating process by logging into the O365 and opening each email one at a time through a browser in EML format.

Limitations of Migrating Thunderbird Email To Office 365 Manually

• Limited to Some Emails: The process to transfer Thunderbird emails to Exchange Online is not meant to move the complete email folder containing over 1000 emails. It can only export some important conversations.
• Lengthy Process: It may take a lot of time in moving each email one at a time to desktop and then to Outlook.
• Time-Consuming: Forwarding hundreds of Thunderbird messages to Office 365 with large attachment files may take a lot of time.
• Data Integrity: Often email formatting or SMTP header is changed for some emails during transfer.

Method 3 Professional Approach to migrate MBOX files to Office 365.

The above-mentioned methods to migrate MBOX files to Office 365 would not be suitable for migrating a huge amount of emails, attachments, contacts, etc. So, it is better to rely on professional software that specializes in exporting Thunderbird mailbox data to Office 365. Using a third-party tool can easily overcome all the drawbacks of Manual methods. You can use the MBOX Exporter Utilityto do this migration easily.

Conclusion

This post describes a long and tedious manual way that is used to migrate multiple mailboxes. It also discusses reasons to make the entire task much easier for administrators. But as you can see manual methods has some drawbacks and also there is a chance of loss of database. So, I recommend you to use a third-party tool to migrate thunderbird to office 365.

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