Our current environment consists of Exchange 2007 mailbox servers on premises with an Exchange 2010 hybrid server. We have most mailboxes up at Office 365, but some are still on premises. For reasons which are out of our control, we want to move the existing on premise mailboxes to a new server, but it must be kept on premise still. I thought of deploying a new Exchange 2013 mailbox server on premises and moving the mailboxes over. Does anyone see any potential problems with running a mix bag of Exchange servers like this?
Daveroo