What if VMware (NYSE:VMW) and its Zimbra email business countered Microsoft (NYSE:MSFT) and Office 365 — plus Google Apps? At first that sounds far fetched. Zimbra is widely available from multiple cloud services providers (CSPs) and third-party hosting companies. But what if Zimbra was available in VMware’s new public cloud — called the vCloud Hybrid Service? Now that could be a game changer.