Zimbra Backend Review

There have been several reviews of the Zimbra Collaboration Suite. However the focus most of these reviews has been on the browser-based Ajax interface. I agree the Zimbra has one of the best, if not the best, browser-based email client. However what makes Zimbra such a great solution is the product as a whole. The focus in this review is the server side of Zimbra.

Zimbra is available for several distributions of Linux® and Mac OS® X. Its architecture includes open-source integrations using industry standard protocols. The third-party software listed below is bundled with Zimbra software and installed as part of the installation process. These components have been tested and configured to work with the software.

• Apache Tomcat, the web application server that Zimbra software runs in.
• Postfix, an open source message transfer agent (MTA) that routes mail messages to the appropriate Zimbra server.
• OpenLDAP software, an open source implementation of the Lightweight Directory Access Protocol (LDAP) that provides user authentication.
• MySQL database software.
• Lucene, an open-source full featured text index and search engine.
• Verity, a third-party source that converts certain attachment file types to HTML.
• Anti-virus and anti-spam open source components including:
• ClamAV, an anti-virus scanner that protects against malicious files.
• SpamAssassin and DSPAM, mail filters that attempt to identify spam.
• Amavisd-new, this interfaces between the MTA and one or more content checkers.
• James/Sieve filtering, used to create filters for email.

Using open source software allows Zimbra to concentrate on improving existing software instead of rewriting software that has already been written. It also allows administrators to use their existing knowledge to configure and troubleshoot Zimbra.

The Zimbra Collaboration Suite is designed to be installed on a dedicated server with no other applications. The installer includes all the necessary components and will install tested versions of the software listed above.

The installer on Linux is command line based and can be run by administrators with little or no command line experience. The default options presented in the installer will meet most administrators’ needs. In less then 15 minutes a single installer will install and configure all the software it needs to run. An administrator will be required to setup DNS correctly for their domain.

The ZCS server key features:

• High availability through clustering, native backup tools, and application level journaling / clustering
• Native hierarchical storage management allows for cost effective multiple GB mail boxes
• Live online move, backup and recovery of individual or a group of mailboxes without a service disruption
• Integrated company-wide anti-spam and anti-virus out of the box
• Easy integration with Microsoft Active Directory and other LDAP directories for authentication and Global Address Lists
• Ease of integration via complete set of SOAP / REST web service APIs and support for Standards (POP, IMAP, iCal, iSync)
• Multi-domain support
• Domain-level administration
• Domain-level branding

Once ZCS is installed almost all administration takes place in the browser-based Zimbra Admin UI. The Zimbra Admin UI is just as easy to use as the Ajax web client and equally powerful. Administrators can quickly:

• Create and edit new accounts
• Manage accounts settings and permissions
• Create and edit distribution lists
• Manage email queues
• View and manage systems status

Full Admin Scripting Tools are also available for large scale / batch operations.

Over the last six months since installing Zimbra I have enjoyed having a mail server with an excellent web-based client. This is important since I use several different computers at multiple locations. I can also use the web-based client from any computer with internet access. Zimbra has also allowed me to have access to all my contacts and calendars from the web-based client. My previous IMAP solution did not support contacts and calendars from within the same system.

The Zimbra Collaboration Suite currently has an open source edition plus standard and professional network editions. The open source edition is a free download and the network editions start at $25 per user. A comparison of the different editions can be seen on the Zimbra site. If you don’t want to maintain your own email server then there are several hosting providers that will manage the server for you. This will also be a cost effective solution if you have less then 20 users. There is a list of hosting providers on the Zimbra site.

For personal use and small businesses Zimbra Collaboration Suite will allow users to enjoy the most common features in Microsoft Exchange without the cost or administrative overhead of Exchange. If you are a business with less then 100 users then I would strongly look into using ZCS as your solution. Zimbra can and is also being used in enterprise environments.