Thunderbird – add a calendar

Thunderbird1) is a cross-platform, fully functional, versatile and free email client, it’s our preferred email client.

1. Install Thunderbird

If you haven’t already, install Thunderbird by downloading it here for Windows or Mac, or from your native Linux repository.

2. Install Lightning etension

If not already installed. You may need to enable this Thunderbird extension.

3. Login to Horde webmail

Login here: Maizymoo Horde webmail. and:

  1. Click on the calendar menu item between “Mail” and “Address Book”.
  2. Your calendars are listed in the left column, under “My Calendars”. There will be a default calendar, you’re free to add more. Calendars are stored in your IMAP folder and as such they will share the mailbox storage with your email. if you run out of space you may not be able to add new events. Please watch your mailbox usage.
  3. Click on the pencil of the calendar you want to add to Thunderbird.
  4. In the window that opens, click on the Subscription tab.

Copy the “CalDAV Subscription URL”. This is the URL that will need to be added to Thunderbird. If you have multiple calendars on this email account you can copy multiple URLs in this way.


4. Open Thunderbird and open a alendar tab

For example by clicking on the top right calendar tab button.

5. Configured calendars

Are shown on the calendar tab, in a list on the left:

6. Add a new calendar

Right click in the calendar list, and select new calendar:

6. Select “On the Network”

When prompted and click next.

7. Enter format and credentials

Select CalDAV as the format. Enter your full email address as user name and your email password. We advise to enable Offline Support if not already selected. Click next.

8. Finished

Next you’ll see the new calendar in the list of calendars on the left. You can change settings like colours by right clicking on the calendar and selecting properties. There the calendar nanme can be changed, the refresh time and options like reminders, offline support and the associated email account.