Zimbra desktop syncs from Zimbra to Google Calendar but not the other way (I'm running Windows 7 64-bit). I deleted both Gmail accounts (only one set up to sync the calendar), uninstalled the program, and reinstalled it, but it still doesn't sync properly. This makes the calendar all but useless to me since I frequently enter appointments in my calendar on my Android phone. I hope this will be fixed soon. I'm trying to replace both Outlook and Google's web site, and this is doing better for the most part than eM Client (the latter is slow in its syncing and it fails to sync even email sometimes).