We've been running both exchange and zimbra in a split domain environment for approximately 4 months now. We are slowly moving people off exchange and dealing with any abnormalities as they show up(which have been very few). A problem that plagues us, though, is how to sync free/busy time and resources across the divide. While appointments work seamlessly across platforms, our main complaint is that users calendars are not visible and resources can not be booked between exchange/zimbra. Getting this to function in the interim would be a big plus. Does anybody have this working? If so, any tips would be greatly appreciated.