There have been some questions recently around whether Hosted Messaging & Colaboration supports using Single Copy Cluster (SCC) for Exchange storage since we seem to focus on Cluster continuous replication (CCR) .

SCC and CCR are both options and both are supported for providing a reliable service. If you already have Storage Area Network (SAN) capacity or knowledge, you can use that with SCC. Otherwise CCR would provide the additional benefit of data availability and the ability to make backup off the passive copy.