I have been lurking for a while, reading posts and articles on the best way to upgrade my current ZCS 7.x implementation to 8.x. I want to move to a newer server platform as well so I will not be doing in-place upgrades of my existing ZCS servers. Any comments on my proposed plan are greatly appreciated...

1. Install new ZCS 8 ldap replica.
2. Promote ZCS replica to master
3. Install new ZCS Proxy/MTA server and one or more ZCS 8 mail stores
4. Move mailboxes from current ZCS 7 mail store to new ZCS mail stores.
5. Decommission ZCS 7 servers

Is the basic logic sound or have I missed something?

Thank you,