I'm setting up a network for a small business with two geographic sites, which will be run on OS X Server.
We need a "chat" tool of some sort, and the contents of those chats could possibly contain sensitive data we can't store on someone else's servers.
Does Apple's Messages app for OS X (Mountain Lion or greater) and iOS fit the bill? I've never set up something like this before, so I'm not sure if every message sent/received via Messages app hits Apple's servers at some point.
If Messages isn't a good fit, please suggest possible alternatives which would work across Mac & iPad?