Horde Groupware Virtual Appliance includes a full working installation of Horde Groupware Webmail Edition. The only two applications installed in addition to the application dependencies are Joe (a simple text editor) and VMware Tools.
Zarafa is an alternative to Microsoft Exchange. It offers the same look and feel of Outlook Web Access (OWA), and fully integrates with Outlook through MAPI. Zarafa Virtual Appliance is a fully working virtual appliance for Zarafa Groupware.