I'ved been trying Zimbra NE. I got my Android device (HTC Desire fw 2.2) to sync with Zimbra. I tried synching just the calendar, and I did get my new Zimbra appointements on the Android device.
But when I deleted one of the appointements from the Android device, it didn't get deleted from the Zimbra calendar (even after a few refreshes).
It seems I accomplished a one way sync from Zimbra to Android. Is this what I can expect, or is there a trick I don't know about?