Is MSexchange not suitable for a user group of less than 80 people?

Question

Microsoft Exchange

There is a need not only for mail and forwarding it between users, but also for general contacts, calendars, tasks, and maybe something more.
The first thing that comes to mind is ms exchange 2013, but in my opinion it is like a heavy Komatsu mining bulldozer, and you need to hill up the beds in the backyard.
Is there anything similar, but a little more compact and less demanding on resources?

Answer 1

Hello
Maybe you should try Exchange Online?
There is also Zimbra, it has similar functionality, but I haven’t tried it myself, I can’t say more

Answer 2

You can try Zentyal or iRedMail

Answer 3

Zimbra is not a bad alternative, but don't expect a lot of functionality from it.