Email - Inbox - View by conversation (see all emails even send and deleted emails) or by message and add a view plane

Email - Powerful Search - (find anything is seconds!!!)

Email - Mini Calendar (hover over date and see all events without switching screens)

Email - Email Identity (use multiple email identities from one location)

Email - Map (hover mouse over address and map pops up)

Email - Zimlet for a PO

Address Book - Create multiple address books and shares with different groups

Address Book - GAL (Global Address List)

Address Book - Sharing

Calendar - View Company, Personal, and Shared calendars at once

Calendar - Event

Calendar - Event Scheduling

Calendar - Sharing

Calendar - iCal Event Sharing

Tasks

Documents - Add attachments or build your own in Zimbra

Documents - Sharing

Archiving and Discovery - Search Definition

Archiving and Discovery - Search Results

IM - Collaborate multiple IMs in one location

IM (more)

Zimbra Desktop (work offline anyplace, even on an plane")