I haven’t played around inside Exchange 2007 as much as I would like to, mostly because I don’t have a machine available that meets the system requirements. Sad, but true. Can’t even run the Exchange 2007 VHD on another PC.
Microsoft has implemented a hosted Exchange 2007 web site that allows you to fully demo the product for five days. Your account will be pre-populated with emails, appointments, and voice messages.
You can send and receive email, adjust client settings, and use Outlook Web Access.
Also check out the series of Exchange 2007 virtual labs