I'm in the need of a solution that let's the company users check their mail from a centralized server (approx 20 users at the moment). We don't run our own SMTP- or web-server and I would like to keep it that way due to time issues. We are using a hosted solution provided by our web hotel and the user's are mostly using webmail or Outlook to check their emails. The fact that our mail also get's screened for spam and virus by our host is a blessing and works great!

What I would like to do, though, is to let the users check their different mail accounts from a centralized server on our LAN. Some kind of "middlehand" so to speak. I would also like this server to act as a intranet with features like shared documents, calendar, messaging, etc. A system with VoIP-integration would also be nice since we're using a Cisco VoIP system right now. So far Zimbra seems to do the job regarding the features!

Here's our planned infrastructure:
We will use 2 domain controllers with Win Server 2003 and Active Directory.
Hardware for the mail mail/intranet server will probably be a HP ProLiant DL380 with dual 3 GHz Xeon's, 3 GB RAM and approx. 600 GB HD (RAID 0+1).
We are going to use a local domain for our LAN ("company.local") and we are currently using 3 different domains (hosted) for our outgoing/incoming mail (with POP3 and IMAP support).

In the future we also might host our own mail server and it would be nice to have a solution is prepared for that.

I've been looking at Zimbra for a while and I really like the looks and the features and also the fact that it's multi-lingual since my native language is not english. I don't now if it's the right solution for us and/or if the scenario I described above is possible to solve using Zimbra?

Thanks in advance and congrats to what seems to be a really nice piece of software!