How to Export Outlook Calendar to Thunderbird? Easy Ways

Written By Ashwani Tiwari
Anuraag Singh
Approved By Anuraag Singh
Published On March 1st, 2024
Reading Time 7 Minutes Reading

Summary: Easily export Outlook calendar to Thunderbird with the simple methods explained in the article. If you have moved from Outlook to Thunderbird or due to some reasons want to import Outlook calendar to Thunderbird, then start reading this article. Here you will find the most reliable and effective approaches to easily sync Outlook calendar with Thunderbird.

Today, emails are considered as the best way for cross-connection among organizations. As the popularity of digitization is increasing, there are so many email applications available in the online market. Microsoft Outlook 2007 and Thunderbird are two such platforms and both email clients store their respective databases (i.e., emails, contacts, calendars etc.) in different file formats. Outlook supports PST file format whereas Thunderbird supports MBOX.

Hence, the motive of this article is to provide you with solutions to export Outlook calendar to Thunderbird, so it is important to talk about ICS format. ICS is a file format that is supported by several email clients to store the information of challengers such as tasks, events, journal, notes, etc. When a user needs to import Outlook calendar to Thunderbird they take help of the ICS file.

In the following write up, we are going to disclose some simple and cost-efficient methods to add Outlook calendar to Thunderbird.

Table of Content

Why Export Outlook Calendar to Thunderbird?

Both of the platforms are advanced and superior, however, there are a few things that users find more suitable in Thunderbird and that’s why they decide to import Outlook calendar to Thunderbird. Such as:

  • Thunderbird export data in MBOX format is quite compatible with other platforms unlike Outlook storage file PST.
  • Thunderbird allows you to install some powerful and useful plugins and make collaboration on Thunderbird much easier.
  • It is a free email application that makes the collaboration cost saving while enjoying several advanced features.

Related Solution:

Method 1: Import Outlook calendar to Thunderbird Using ICS Format

Here, we are going to use Thunderbird Lightning to export Outlook calendar to Thunderbird. Lightning is a Mozilla Thunderbird add-on that enables users to schedule group meetings, assign the tasks and appointments.

Note: It is recommended to follow the guidelines sequentially to avoid any kind of data loss while exporting Outlook 2019, 2016, 2013, 2010 calendar.

  • Open Microsoft Outlook sync Outlook calendar with Thunderbird.
  • Select Calendar for Thunderbird Outlook calendar.
  • Choose the File drop-down menu and highlight Save Calendar.
  • Enter a file name and select iCalendar format in Save as type section. Click Save.
  • Choose the Whole Calendar as Date Range. Hit OK button.
  • Download Thunderbird Lightning from the official site of Mozilla
  • Go to the Add-On section in the right panel and configure the Lightning.
  • Now, launch Mozilla Thunderbird.
  • Click on the right panel and select Events and Tasks.
  • Choose “Import” from the drop-down.
  • Click on Browse button and select the iCalendar file that you have exported from Outlook.
  • Click OK to add Outlook calendar to Thunderbird.

So that was the final steps to import Outlook calendar to Thunderbird

Method 2: Export Outlook Calendar to Thunderbird Using GAMMO Tool

Go through the following set of instructions to attempt the procedure to sync Outlook calendar with Thunderbird:

Step 1. Export Calendar from Outlook

  • Launch Microsoft Outlook to add Outlook calendar to Thunderbird
  • Click on File tab and select Open & Export >> Import/ Export
  • Here, choose Export to a file option. Click Next
  • Select Outlook Data File (.pst) option and click on Next button
  • Select Calendar and click on Next
  • Browse a location to save the resultant file and name it
  • Eventually, click on Finish to for Thunderbird Outlook calendar.

Step 2. Import PST to Gmail Account

  • Download and install GAMMO tool on your computer

Note: Microsoft Outlook installation is necessary to import Outlook calendar to Thunderbird.

  • Now, launch GAMMO application and enter the email address of your Gmail account. Click Next
  • Select the Gmail account to import PST file
  • Next, grant the permission to the software to execute migration via hitting the Allow button
  • Select From PST file option and choose the Outlook Calendar file that you need to import. Click Next
  • In Migration Settings window, check the Calendars option and hit Migrate button
  • After completing the process successfully, a message will pop-up. Click OK
  • This will import the Outlook file to your Gmail account. Follow the next step to export Outlook calendar to Thunderbird completely.

Step 3: Configure Gmail Account in Thunderbird

  • Enable IMAP in your Gmail account.
  • Then, open Thunderbird to add Outlook calendar to Thunderbird.
  • Go to Create a New Account box and choose Email.
  • In Mail Account Setup window, enter your name, email address, and password.
  • After filling all these details, click on Continue button.
  • Next, enable IMAP (remote folders) checkbox and click Manual config.
  • Now, enter the following settings manually for Server hostname section:
    • Incoming: Port: Either 993 (SSL).
    • Outgoing: Port: Either 25 or 465 (SSL).
  • Click on Re-test to import Outlook calendar to Thunderbird.
  • If you have entered all the details correctly, then click Create Account.
  • If Mozilla Thunderbird is asking to authorize the Gmail account via Thunderbird then, permit the access to Thunderbird for syncing your Gmail data with Thunderbird.

Eventually, the Gmail account will be successfully add Outlook calendar to Thunderbird. Setting up a Gmail account in  Thunderbird enables users to access the complete email data of Gmail in Thunderbird. So that, users can also access their Outlook calendar easily from Thunderbird after this.

Method 3: Automatic Way to Add Outlook calendar to Thunderbird

To export Outlook Calendar to Thunderbird users can opt a trouble free and quick solution i.e., SysTools Outlook PST File Converter tool. It is a well-developed software to export data from PST file to multiple formats. It software is not only helpful to add Outlook calendar to Thunderbird from active Outlook account, but also import Outlook calendar to Thunderbird from an orphan PST file. Moreover, it offers several more useful features to ease and the task and make it more efficient and quick.

To import Outlook calendar to Thunderbird on Windows, follow the steps mentioned below:

Download Now Purchase Now

How to Add Outlook Calendar to Thunderbird with Tool?

Step 1. Launch Tool and Add Calendar File in the panel

add calendar pst file

Step 2. Preview items and choose Folder to export to import Outlook calendar to Thunderbird.

preview calendar items

Step 3. Choose ICS file format from the saving options.

Export Outlook Calendar to Thunderbird

Step 4. Click Browse and choose the location to save resultant file

save ics file

Step 5. Click on Export button to start the conversion process to export Outlook calendar to Thunderbird.

Transfer Outlook Calendar Events to Thunderbird

Steps to Sync Outlook calendar with Thunderbird on Mac are;

Step 1. First download and install the Mac conversion software.

Download Now Purchase Now

Step 2. Add Calendar file in the software panel.

load calendar file

Step 3. Pick ICS file format from the list.

choose ics file format

Step 4. Select path for saving resultant file and click Export.

export outlook calendar to thunderbird

Once the conversion is done to sync Outlook calendar with Thunderbird, it will display a message box showing the completion. Also, it will show the path of the converted PST file.

In order to verify the process, go to the location where you have saved the resultant ICS file and import Outlook calendar events to Thunderbird.

Now, you can easily import ICS file in Thunderbird by following these simple steps:

  1. Open Thunderbird and click on Events and Tasks from right side.
  2. Here click the Import option.
  3. Select ICS file to import in Thunderbird.

Author Suggestion

Outlook is a Personal Information Manager that allows exchanging emails, managing contacts, calendars, tasks, notes, journal entries, and much more. It saves all its mailbox data in a single file with the extension .pst. In order to import Outlook calendar to Thunderbird, both manual and automatic techniques are discussed in this write-up. So, users can choose any of them to export Outlook calendar to Thunderbird as per their suitability and conversion requirements.


By Ashwani Tiwari

Being a Chief Technical Analyst, I am aware of the technicalities faced by the user while working with multiple technologies. So, through my blogs and articles, I love to help all the users who face various challenges while dealing with technology.