The Zimbra Collaboration Server is a mail server, collaborative web application and a web based mail server admin console in a single application. It provides LDAP, antivirus, antispam, collaboration features and a ajax webmail client. Zimbra is easy to use for administrators as well as end users due to its fast Ajax based web interface.
Zimbra is an Open Source mail server application which provides many features and is easy to use for admin and client. Zimbra requires a lot of server ressources, so dont use it on servers that do not match the base requirements outlines in the first chapter.
Here is the step by step installation of Zimbra Mail Server :