Thunderbird is a feature-rich and mature mail client that can be turned into a full-fledged PIM. However, it lacks support for address book synchronisation via CardDAV and it also lacks the ability to automatically discover calendars and address books available on the server. Therefore, to synchronise with Nextcloud, add-ons are required, which can be easily installed through Thunderbird’s add-on manager.
Synchronizing with Thunderbird¶. Thunderbird is a feature-rich and mature mail client that can be turned into a full-fledged PIM. However, it lacks support for address book synchronisation via CardDAV and it also lacks the ability to automatically discover calendars and address books available on the server.
Persistent sticky notes for Thunderbird associated to mails. In TB 78, you can define the note position in the settings. If you have a large screen, you can even display the notes outside of TB's main window, so it won't hide anything.
I understand a Thunderbird iCloud calendar sync may be a niche use case. However, if you're stuck with it you don't care how much of a niche it is. You'll want clear instructions how to fix you problem, that is how to add an iCloud calendar to Thunderbird - and you'll get just that here.
For this method, you need to have three add-ons installed:
The Lightning calendar
TBSync and
The TBSync provider for CalDAV and CardDAV
When they are installed, if you are on Windows, go to Extras/Synchronisation settings (TBSync) or Edit/Synchronisation settings (TBSync) if on Linux
In the account manager choose “Add account / CalDAV / CardDAV account“
In the next window, go with the default called Automatic configuration and click next
Enter an an account name, which you can freely choose, user name, password and the URL of your server and click next
In the next window, TBSync should have autodiscovered the CalDAV and CardDAV addresses. When it has, click Finish.
Now check the box Enable and synchronize this account. TBSync will discover all address books and calenders your account has access to on the server
Check the box next to each calender and address book you want to have synchronised, also set how often you want them to be synchronised and push the button sychronise now
After the first successful synchronisation is complete, you can close the window. Henceforth, TBSync will do the work for you. You are done and can skip the next sections (unless you need a more advanced address book)
Alternative: Using the CardBook add-on (Contacts only)¶
CardBook is an advanced alternative to Thunderbird’s address book, which supports CardDAV. You can have TBSync and CardBook installed in parallel.
Click the Cardbook icon in the upper right corner of Thunderbird:
In Cardbook:
“Adressbook > New Adressbook Remote > Next
Select CardDAV, fill in the address of your Nextcloud server, your user name and password
Click on “Validate”, click Next, then choose the name of the addressbook and click Next again.
When you are finished, CardBook synchronizes your addressbooks. You can always trigger a synchronisation manually by clicking “Synchronize” in the top left corner of CardBook.
The old method: Manually subscribing to calendars¶
This method is only needed if you don’t want to install TBSync.
1. Go to your Nextcloud Calendar and click on the 3 dotted menu for the calendar that you want to synchronize which will display and URL that looks something like this:https://cloud.nextcloud.com/remote.php/dav/calendars/daniel/personal/
Go to the calendar view in Thunderbird and right click in the calendar menu to the left (where the names of the calendars are) to add a New Calendar.
Choose On the network
Choose CalDAV and fill in the missing information:
Fix for Thunderbird 60¶
If you are still using Thunderbird 60, you need to change a configuration setting to make CalDAV/CardDAV work around Thunderbird bug #1468918 as described here
I do want to add that TBSync v2.16 is known to also work with setting up iCloud and Google calendars as well (for those needing Exchange ActiveSync, that one has been updated. You can download it here).
TBSync is very spotty with maintaining a solid connection to iCloud (in TB v78) and will not tell you or give you an error message to let you know it isn't syncing. But the devs for TBSync have a good reputation so I am sure that it will be updated soon. :) MHO
With TBSync currently you won't be able to change the names of the calendars as they are being directly synced with the account, lest you drop the connection to that account. [When TBSync pulls all all calendar info (and associated sub-calendars (by their names) from that account) it dumps them into a collective group in TB v78, like ({Google) <calendarname>).
Thunderbird Tbsync Download
So the above option will allow you to keep the original names without having the calendar names prefaced with the name of the account ('Google,' 'iCloud,' or whatever the general account name is.