Mozilla Thunderbird


Unfortunately, Mozilla Thunderbird can only handle email on its own. In order for it to also deal with your contacts, appointments and tasks, third party extensions are required. Therefore, you need to set up all of those separately. We show you how to do that below.

E-Mail Setup

When you start Thunderbird for the first time, it will ask you to create an account. Please say that you want to use an existing email address.

The following dialog should appear where you can enter your account credentials. Click Continue and Thunderbird will attempt to find the correct settings automatically.

If the automatic configuration detection fails, enter the credentials for incoming and outgoing servers as depicted below:

Click Done to re-test the configuration and finish the setup.

Calendar Setup

In order to use calendars with Thunderbird, you need to first install the Lightning Add-on, if you do not have it already. Then switch to the Calendar tab and in the bottom left corner right click below your local Home calendar. A context menu will pop up where you can select New Calendar.... In the following dialog you say that your calendar is On the Network, then click Next. On the next screen, please select the CalDAV format and enter the following address:

The above URL will usually only work for the standard Calendar that is set up initially. In order to add your other calendars, please repeat this procedure and use the CalDAV URL that the option Show Calendar URL from the Webinterface will get you. To get this URL, please login to and then follow the following steps:

  1. Select Calendar in the top right corner drop-down menu
  2. Select the calendar you wish to add to Thunderbird/Lightning with a single left click in the lower left corner. The selected calendar should visibly highlight.
  3. Next click on the small gear symbol below
  4. From the menu you’ll see, please select Show Calendar URL
  5. In the window that will appear please copy the second URL (where it says CalDAV)

This is the CalDAV URL you have to use in the above procedure in order to add any calendar to Thunderbird/Lightning.

Tasks Setup

If you want to synchronize your tasks with Thunderbird, you can follow the steps from the Calendar Setup and add a “calendar” with the following address:

Now your tasks should show up in Thunderbird as well.

Address Book Setup

In order to use your Kolab Now address books with Thunderbird, you need to first install the SOGo Connector Thunderbird extension, if you do not have it already. Then click the Address Book button and in the Address Book window, go to the menu, choose File > New > Remote Address Book. On the next screen, please enter the following address:

In order to add other address books, please repeat this procedure for each address book. You can get the URL for the address books the same way as described above in the Calendar Setup.

Trick: Enable Multiple Accounts

By default, Mozilla Thunderbird just support one calendar and one address book account per server. If you have more than one Kolab Now account, you need to use the following trick:

  1. Go to Edit → Preferences → Advanced → Config Editor…
  2. Search for
  3. Double-click to set the value to true

Then restart Thunderbird, add the second account and enjoy the full power of Kolab Now!