I am totaly new in zimbra mail server. I have my Exchange Infra configured and i wanted to replace my exchange Infra with new Zimbra infra. now i wanted to install zimbra collaboration suite (open source) on my cen os server in cluster environment. I have min 300 to max 2000 users will be host on this zimbra server. I wanted to know the basic hardware & software requirement to set up ZCS on centos cluster and step by step process to install it including cluster on centos. can any one help me to configure this setup and provide me the documents for the same.