We’ve just set up a Zimbra server as a trial in the office to use as a groupware solution – hopefully avoiding the Microsoft tax of Exchange.
First glance seems good, but it really highlights the deficiencies of the open source world in this area – Thunderbird/Lightning/Sunbird need a lot of work to catch up to Outlook/Exchange. Looks like they’re on the right track though.
Anyway, the first thing I tried to do was connect my Thunderbird/Lightning install with the Zimbra server. The documented method on the official wiki only included reference to connecting to your calendar via ICS using the webcal:// format.
Not really sure what it’s doing on the back end there, but I immediately ran into problems deleting events – a quick Google indicates many other users have the same problem. Fortunately in some other forum post (which I can’t find any more) I saw reference to Zimbra getting CalDAV support, which seems to work fine.
I’ve updated the wiki page above, but figure it’s worth saying again because it doesn’t appear to be widely known.
The CalDAV URL for your calendar is just:
It should possibly also be noted that you cannot map your Tasks in this way – ICS seems to be the only way to do that.