I currently have a (non-clustered) 32bit ZCS6 system with about 200 mailbox users on it.
I know that this is a dead end, so I'd need to migrate to 64 bit before I can go to ZCS7. At the same time, I'd also like a clustered setup (with 2 or 3 mailstores), as I need to add about 75 heavy users the next 2 months.
How do I do this? Can I "add" a new ZCS7 to the existing (single-server) setup? Or is it better to just setup a new ZCS7 server, and migrate the old accounts during one big planned maintenance?