I don't know how unique our situation is but I think the needs are pretty strange and we're trying to figure out whether Zimbra can be the magic bullet.

First, we already use Apple's Mail server and we're pretty happy with it. What we're lacking at the moment is a workable calendaring solution. So my first question is, can Zimbra be used as a calendaring solution only with Apple Mail/Outlook/OS X Server handling email and Zimbra handling calendaring?

Our Calendaring Utopia:

We have about 50 windows pc's and 350 Macs. The PC's and Macs need to play nice. We currently use Meeting Maker which is working well for us internally but it's having a problem interacting with our customers' Exchange systems (they are inviting the PC users at our company to meetings).

Our dream solution would allow these Windows users to use Outlook (which can interact with our customers' Exchange systems) and have our Mac users use iCal. This way the PC users can interact internally with the Mac users and externally with our customers. The solution would allow us to kill off our Meeting Maker license which is quite pricy.

We're a few versions behind the shipping version of Meeting Maker and I'm fairly certain the shipping version will do what we want but it's more expensive than Zimbra so we're exploring the possibility.

Does anyone out there have experience with this type of scenario?