Dear Community,

We are currently a primarily Windows house with ~60 users. We (the IT staff) are tired of Microsoft products and hate Exchange. We're also questioning the logic of in-house email/ groupware in general. It seems to take a lot of our time - and cause anxiety (constantly on call for email issues, archiving/ disaster recovery, etc.)

We are generally interested in Open Source products (or at least good APIs) so that we can change things or extend functionality, if we need to. Our primary need is for mail and calendaring - but sharing documents is nice. These are our main contenders so far (and concerns):

- Google Apps (poor support?)
- Zimbra (Yahoo might be purchased by Microsoft?)
- OpenXchange (needs more research - doesn't seem to be a lot of people using it as a hosted solution)

Would also like to hear any arguments for keeping things in-house. Keep in mind, we have ~60 users and 2.5 IT resources (1 programmer, 1 IT manager and 1/2 desktop support).

Any tips would be greatly appreciated.