Some of the items you may want to check.
1. what version of Zimbra are you running?
2. Is your public zimbra server name the same server name used for your zimbra install?
3. What is the output of https://mail.yourzimbraserver.com/dav/<username>?
The reasons for that, when I first installed zimbra, I installed with the server name different than the one I planed to use for public. and I found alot of referral links will point back to zimbra server name cause my SSL certificate to fail due to invaild server name than the one specificed in the certificate. not to mention my zimbra host name can not be resolved in public network. I follow the procedure to rename my zimbra hostname and that solved a lot of the CalDav Issue I had with Thunderbird and Lightning.
On the /dav output. see if you can use the info there get an CalDAV URL without @domain.com. I have find many cases not using the @domain.com in the username work much better. This may not be possible for multi domain installation but it's worth a try.  |