Zimbra Collaboration Suite for Ubuntu is a innovative messaging and collaboration. Zimbra Collaboration Suite offer administrators and their end-users unmatched benefits and TCO. Zimbra is email server base. ZCS features include Ajax web client integrating email, contacts, shared calendar, enterprise mash-ups, VoIP, and online document authoring and-sharing. Also included with ZCS is a complete server solution with built in anti-spam, MTA, storage, authentication, and admin features.