Office 365 to Thunderbird – Migrate Mailbox Mails & Other Data

Office 365 is being used among users for its emailing and several advanced features. However, it has been observed that several users demand to switch from Office 365 mail to Thunderbird. Mozilla Thunderbird being one of the best and free email client has been prominent choice of users for a long time. Due to several advantages offered by this desktop email application, users wish to move their O365 user account to Thunderbird. In this section, we will discuss how to configure Office 365 account to Thunderbird so that the users can easily access their O365 mails and other data items in Mozilla Thunderbird application.
Let us discuss about the user queries regarding the export of Office 365 to Thunderbird.

User Queries on Export Office 365 Mail to Thunderbird

“I work for an NGO and I am having a meeting with my clients at a remote location where I won’t be having any internet connection. I am currently using Office 365 for emailing purpose. I need to export important emails from O365 to my local drive or laptop. Please suggest what I should do.”

Paul Loki

“How to do I migrate my entire mailbox from Office 365 to Thunderbird? I need quick & easy approach to do so. I am in a hurry for a solution as I have been looking for one since ages!! Please help me with relevant procedures! Thanks in advance!”

Lizzy Done

“I am using Microsoft Office 365 and I really like using OWA but I was wondering that is there any way to access my mailbox even if I am not connected to the internet? It would be great if I would be able to view or access the emails of O365 offline!”

Andrew Gartner

Why to switch from Office 365 to Thunderbird

Many users attempt to move to Thunderbird so that they can easily access their data on the local desktop location. Some of the possible reasons behind transfer from Microsoft Office 365 account to Thunderbird include:

  1. Since Office 365 account needs to be renewed after a specific period of time. So, the users prefer to switch all their emails and other data to freely available Thunderbird account. It makes them access the emails at free of cost. Thus, free availability of Thunderbird is one of the major reason behind migration.
  2. Office 365 being a web based service maintains repository of data on the server end. Sometimes, due to unexpected breakdown or shutdown of Exchange server, it becomes difficult for the users to access data from the mailbox.
    However, Thunderbird being a desktop application stores entire data at the local location. The user can easily access mailbox items without depending on additional platform. Thus, this platform accessibility makes user to move their data from Office 365 to Mozilla Thunderbird.
  3. Office 365 provides access only in the online mode. The users cannot access the existing mails from mailbox in offline mode. However, Thunderbird allows the users to access the mailbox data even in the offline mode. Thus, users find it more convenient to use Thunderbird as it does not impose any restriction on accessing the mailbox without internet connection.
  4. Thunderbird allows the users to share data easily as all the files are located at local location. So, the users can easily share data even without internet access. However, sharing data through Office 365 requires internet connection, which makes its use limited.

How to Export data from Office 365 Mail to Thunderbird

The following are the two methods to move/ connect O365 mailbox to Mozilla Thunderbird & also transfer all the data to the latter.

Manual Procedures to add Office 365 Mail to Thunderbird

While migrating to alternate email application, the major concern of every user is to retain the existing mailbox. The user always desire to access the mails and other data items from Office 365 in Thunderbird account. The following manual method facilitates to move data from Office 365 to Mozilla Thunderbird:

  1. Under Thunderbird, browse File > New > Get New Mail Account.
  2. Click on Skip & use my existing email option to configure the Office profile.

  3. Enter your name, which is to be viewed to others. Also, provide email id and click Continue.

  4. Manually configure the account under mail setup wizard.

    Enter the following credentials to configure Office 365 to Thunderbird:
    → For Incoming Settings
    Incoming Server- IMAP
    Server Host Name-
    Port Number-993
    Authentication-Normal Password

    → For Outgoing Settings
    Server Host Name- smtp.domain
    Port Number-465/587
    Authentication- Normal Password

  5. Select Done option to save the manual configuration.
  6. Enter your password for Office 365 to authenticate and download all data into Thunderbird.

    Using this Office 365 to Mozilla Thunderbird export method, the user can download emails from Microsoft O365 account and access them in Thunderbird.

Limitation of Manual Method

It has been reported that the manual procedure does not download all the messages to new account and often leads to loss of data. This makes it problematic for the users who wish to maintain data integrity and consistency while they export Office 365 to Thunderbird.

Automated Approach to Migrate Office 365 to Thunderbird

An alternate efficient approach, which provides complete extraction of O365 data is Office 365 Backup utility. It offers the users to migrate the O365 emails directly into Thunderbird supported file format.

The tool carries out migration of Office 365 data items in the following steps:

  1. Enter the login credentials for MS O365 account under logging window.

  2. Choose Office 365 Backup option to extract mailbox emails.
  3. Select the mailbox emails, which you need to transfer from Office 365 to Mozilla Thunderbird account.
  4. Browse the location for storing resultant files.
  5. Select option from the mentioned file formats.

The software creates a file, which can be easily opened with Thunderbird. It helps in migrating Office 365 mailbox to Thunderbird.

Frequently Asked Questions

Does this third-party utility helps to directly configure MS Office 365 contacts to Thunderbird?

No, this tool does not allow you to import contacts from O365 directly to Thunderbird.

Is it possible to add Office 365 account to Thunderbird on Linux system?

Yes, you can readily link Office 365 to Thunderbird application on Linux.

Does Office 365 allow to share news articles through NNTP?

No, O365 does not support NNTP protocol. So, you cannot share articles using this application. You can migrate to Thunderbird for sharing the files using NNTP.


Understanding the need to connect Office 365 mail to Thunderbird, we have discussed the manual method as well as automated approach for mailbox transfer. The users can easily switch within client applications without any data loss by using these methods. We have also discussed the limitations of manual method & an alternative method to perform export of Office 365 to Thunderbird