Not the chopped down OSX thing that you can get for $20 that seems to have all the best bits taken out of it.
Small office, 5 users, need centralised server and email to reduce data usage over 4G, ideally download once in one place, i.e. server and share locally over LAN. They are all MAC. If I was doing this with Windows I’d go for Server Essentials on a decent PC with a virtual POP/IMAP server amalgamating all external accounts into a central place for access by machines in the office via personal accounts - which may still be an option if there is no decent MAC solution.
Yes the Linux way points to the right direction! Just a plain Debian or Ubuntu Server with Postfix and Samba Services installed. Or if you wanna walk the easy path: A QNAP NAS. Whatever you choose, place it behind a firewall (already mentioned in previous thread).
IMHO Windows Client-Server Model is dead and basically a piece of bloatware with high hardware and administrative demand. Sooner or later you will find yourself in a Lock-In position. We all saw Microsoft’s Vision on “World Computer”, Cloud and “the Edge” couple of weeks ago during BUILD.
I’m probably going to end up moving my customers with Mac servers over to a linux solution. I have ISPConfig running in a couple of places and it seems to do what I need in terms of email and web services. Still not sure what to do for people using calendars other than compiling apple’s solution myself. At least apple put up instructions on how to compile everything.