Zimbra Collaboration Suite (ZCS) (www.zimbra.com) is an open-source web-based collaboration suite providing messaging, calendaring and PIM functionality as well as document creation and sharing.
Running on Linux, the ZImbra installation package contains all of the pre-requisite components the solution requires, including PostFix, MySQL, Jetty web server and OpenLDAP. Supported Linux distributions include Red Hat Enterprise Linux 4 and 5 - I have had success with the CentOS variation of RHEL, using CentOS (www.centos.org) version 4.7 to create this article.
Zimbra supports standard email messaging protocols including SMTP, POP and IMAP. Anti-spam service is also built-in with the inclusion of SpamAssassin.
This article is designed to provide an overview of the ZImbra solution only, more detailed information can be found on the Zimbra web site - www.zimbra.com
Installation
Install a base installation of CentOS only - as mentioned above the ZImbra installation package contains all of the components it requires - having any web or email services running may lead to port conflicts which will generate errors during the installation.
If you intend to run Zimbra as a standalone machine then do install the DNS server role.
Zimbra requires at least 5GB of available hard disk space.
The /etc/hosts file will need to be edited, by default it will probably look like this:
127.0.01 zimbra.domain.com zimbra localhost.localdomain localhost
Edit it so that it looks like this:
127.0.0.1 localhost.localdomain localhost
192.168.0.10 zimbra.domain.com zimbra
(where 192.168.0.10 is the IP address of the Zimbra server)
To configure DNS (if required), you may want to install Webmin (www.webmin.com). Create a master zone for your domain as well as A and MX records for the ZImbra server. Also remember to set the server's primary DNS server to the localhost address.
On my Centos 4.7 installation there were a number of pre-requisites I had to install:
GCC can be installed via yum - issue 'yum install gcc' at the command prompt
Fetchmail can be installed via yum - issue 'yum install fetchmail' at the command prompt
LibTool can also be installed via yum - issue 'yum install libtool' at the command prompt
Three further components were required, which can be downloaded and installed as RPM packages:
compat-libstdc++-296 - available from:
http://rpm.pbone.net/index.php3/stat/4/idpl/8963867/com/compat-libstdc++...
compat-libstdc++-33 - available from:
http://rpm.pbone.net/index.php3/stat/26/dist/56/size/21536729/name/compa...
libstdc++.so.5 - available from:
http://rpm.pbone.net/index.php3/stat/4/idpl/8962252/com/compat-libstdc++...
Once all of the pre-requisites have been installed you are now ready to install Zimbra.
The installation package will have been downloaded as a TAR file, extract the contents with a 'tar -xvfz zcs-x.x.x.tar.gz'
Once exctracted, change to the created directory and issue the command:
./install.sh --platform-override
The platform override switch is required if you are using a non-RHEL Linux distribution, but I did not have any problems on CentOS.
The installer wizard will now launch, follow the on-screen prompts. This process may take a while (approximately 20 minutes on my virtual machine), but you can leave most of the options at their default values.
Verify Installation
Provided that everything went according to plan, you should be able to browse to the IP address of the Zimbra server from a web browser and will hopefully see the ZImbra login in page:

Login using the admin account with the password you specified during the installation wizard, the main ZImbra web interface will be displayed:

From here users can read, forward, reply to and delete email messages, access calendar, contact and task folders, etc.
The Documents feature adds an extra level of functionality to the solution, enabling users to create and share web documents:


Zimlets are optional plugin modules that can be downloaded and installed onto the Zimbra server to provide additional functionality to the default user web interface. By default a Yahoo! Zimlet is installed that provides one-click access to the Yahoo search engine. A wide range of Zimlets are available online including plugins for Yahoo Maps, Flickr, web-SMS tools, etc.
Administration
The ZImbra administration console is accessed via a web browser by browsing to https://(zimbra_server):7071
Hopefully you'll see the following:

From here the administrator can add, remove and edit user accounts, groups and domains as well as defining mailbox and security policies.
It is beyond the scope of this article to go into the administration of the solution in any depth.
Zimbra Desktop

Unlike Scalix (http://blog.brightpointuk.co.uk/node/134), another open source email platform, which has very shrewdly developed a plugin that enables the solution to be accessed from Microsoft Outlook, Zimbra (now owned by Yahoo!) have developed a client application for Windows. Not limited to accessing a Zimbra email server, the client can be used to access a wide range of POP or IMAP-based email service providers. Installation and configuration is quick and easy:



The client can be configured to access the Zimbra server either via POP or IMAP or equally via HTTP port 80, effectively acting as a web-based client.