We are a k12 district that more and more people are starting to ask about shared calendars.

We currently have a qmail server running without issues for many years now, we have since put an exim server in front for more spam/av control and have been quite impressed with what we have been able to do.

But when it comes to shared calendars and the dreaded 'global address book' this is where OpenSource apps seem to be lacking.

So looking for a solution that doesn't break the mental capacity of our shrinking IT department.

We are using samba and cups for file and print sharing and using a handful of scripts with rsync and txt files to populate and keep things in sync.

So the questions..

What can we expect from Zimbra *without* an AD server or anything from microsoft on the backend.
- and with what functionality we loose without an AD server, does zimbra have anything to overcome what is lost?

Not that we push Outlook, but does Zimbra replace Outlook (which would be great) or can it work with it?

Thanks in advance.