GateSuite allows you to be part of the Cloud and provide your own services. Assemble your own, virtual products, and resell them to have your customers filter their email through your virtual gateways – while not having to provide your own hardware.
Clustering is already built-in to Gate-Suite. You are however not limited to one single location. Span your Gate-Suite across multiple sites to get resilience and fault-tolerance for large-scale networks. The policy manager even allows you to have per-site rules, that apply differently to your various cluster members and locations.