Setup office365 calendar with Thunderbird

In order to integrate Thunderbird with Office 365 Calendar, you will need to download and install few additional plugins for Thunderbird.

Although the instructions and samples were created setting up Thunderbird on a Ubuntu Linux box they exactly the same across all operating systems (i.e. Windows, Mac OSX )

The Thunderbird email client does not come pre-packaged with a calendar option, however there are plenty of free Extensions you can download to incorporate a calendar feature.

The prefered calendar add-on is Lightning which allows you to organize your schedule directly within Thunderbird.


Install Lightning

In order to install the lightning plugin. Navigate to Tools –> Add-ons on your Thunderbird Menu.

In the search box search for lightning

This should return a few results, so pick the top one. at the time of writing this was Lightning and click install, once the install is completed you will need to restart Thunderbird.



Once installed you may be asked to Restart Thunderbird


Install Exchange EWS Provider Add-on for Lightning

We now need to install an additional plugin integrate your Calendar with Office 365. In order to do this you need to download and install Exchange EWS Provider Add-on for Lightning. At the time of writing this article the latest version was 3.8.0.

Exchange Calendar

Check out the code on GitHub

Available on Github

Visit the GitHub page and right click on the link exchangcalendar-v{version number}.xpi and select Save Link As...

This will download the the plugin. To install the plugin got back to your Thunderbird Addon and click on Cog Icon and select

Install Add-on From File


Navigate to folder to which you downloaded the file to and install the plugin. You may be asked to restart Thunderbird again.


Configure your Calendar

All the installation is now complete, all we now need to do is set up a calendar and you’ll be up and running.  To do this you need to navigate File –> New –> Calendar, 
This will open a new dialog, select On the Network and Next

Create new calendar dialog


Select Microsoft Exchange 2007/2010/2013 and Next


Give your Calendar a name and click next


create new calendar dialog next

Fill the Server URL: or
and enter your email address for Office 365 and click Check Server and mailbox


Click Check server and mailbox

You should see an input dialog for your password, enter your password, and check the to save it.  Clicking next will complete the process, and you should now have your Office 365 calendar set up on Thunderbird.


You should be able to Click Next and Finish.


Your calendar is now Available and you are able to do 2 way editing of your calendar appointments etc.


If you have any issues or found any variations in the process. Please let us know in the comments below and I will try to assist as much as we can.

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Gary Woodfine

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  • Dorin Chiritoiu

    Great article! However, I would to ask smth.

    Does this method allow 2-way sync? I mean to write something on Thunderbird/Lightning calendar and see it on Outlook calendar? I am asking this because I have a Windows Phone 🙂

    • ThreeNineConsulting

      Yes it does. You’ll be able to update your calendar from both Thunderbird and your phone and the updates will be synchronised

    • In the search box search for lightning

  • Jonathan Xavier

    Just a small update:
    The link to the calendar is:

  • Awesome! Worked perfectly, thank you for sharing!

  • Christian Brolin

    My button in the second dialogue is disabled. Probably because the field is empty. I have no idea what this field should contain. Location of what? In your example it contains “https::/auto/” followed by a large number of hexadecimal digits. You didn’t mention where you got them from or that you did something to get them there. Seems to me that something important is missing.

    • Hi Christian,

      This should be automatically populated when configuring. As you can see in my Screenshot is is greyed out, as it is disabled.

      What Operating system are you using i.e. Windows, Mac or Linux?

      I can try go through the installation process again our side, to see if we can find any anomolies. However, from memory I didn’t enter any data into that field, it was just auto-populated. Unless these has been a change in configuration with the plugin itself I am unsure what else could be wrong.

  • Dick van Vlooten

    hi, I managed to get a connection, via outlook (not office365) on WIndows 10, 3.90 version, thunderbird 52.2.1. But: It does not sync and the icons tell me it is read only. What more do I need to do? I want to be able to sync 2 ways, if possible
    many thanks in advance


    • Dick van Vlooten

      If I click on the agenda in Thunderbird, I can untick the READONLY tickbox. But that doesn’t stick . . . .

      • Dick, I can only assume that there may have been a difference in the version of the ExchangeCalendar .xpi you’re using. I am currently making use of the 4.0.0beta4 and I don’t have any issues

  • Joost van Putte

    I’ve got it all installed and working, am using the latest version of EWS (4.00 beta4) and Thunderbird (52.5.0) on mac and windows 10. If I create a new event it perfectly syncs it with the shared/online calender.

    But it does not sync any events already in the calender to my local agenda calender. And I haven’t gotten a clue why.

    Have you got any clue how to get the events imported?

    Greatly appreciated!

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