I know that this is probably futile, but I'll ask anyway. Would you (Yahoo/Zimbra) consider making a MacOSX version for the G4/G5 platforms available? There are millions of these machines out there, and unlike Windows platforms, they never quit working. I am writing this from a 10 year old PowerBook G4, and at my office, I use an equally ancient G4 PowerMac in preference to a glitzy 3 GHz Dell PC that the company would prefer I use. I think there are a LOT of people like me out here. Please consider supporting us.
PS: I used the ZCS open source server/client edition on G4 Macs for years, and was really looking forward to using this new client.