What is Zimbra | Zimbra

Alert! This article is written for Zimbra OSE users. As of December 2023, Synacor will no longer be providing support for Zimbra OSE. You might want to consider trying out Carbonio Community Edition – Zextras’s free and open-source email and collaboration platform.

For additional guidance, check out our community articles detailing the process of migrating from your current platform to Carbonio CE.

Zimbra is an open-source software product for automating and simplifying collaboration between any workgroup, whether public or private. Zimbra, with an active developer community and global partner network, is the third largest collaboration provider in the world, used in more than 5000 companies and by over 100 million users in more than 140 countries worldwide.

Zimbra Collaboration Suite

Zimbra Collaboration Suite is an enterprise-class collaboration solution for email, calendar and office tools. It combines the corporate cloud with email and project management capabilities, making ZCS a very interesting solution especially for large companies

Basic features of Zimbra Collaboration Suite:

  • Delivery, storage and dispatch of e-mail.
  • Mail indexing.
  • Mail server logging.
  • Supports IMAP, POP, CalDAV and CarDAV protocols.
  • Directory service.
  • Antispam protection (Spam Assassin).
  • Antivirus protection (ClamAV).
  • Synchronization with mobile platforms: Android, iOS, Windows.

Zimbra Editions

Zimbra Collaboration Suite comes in two main editions:

  • Zimbra Open Source Edition, which is a completely free version of Zimbra, containing all the basic functionality.
  • Zimbra Network Edition, which is a paid version of Zimbra featuring which has additional features compared to the Open Source version.


Zimbra Collaboration Suite consists of client and server software and the following application packages:

Zimbra Core – Includes libraries, utilities, and base configuration files.

Zimbra Store (Zimbra server) – It installs components for the mail server, including Jetty, which is a servlet container that runs the Zimbra software internally. In the Zimbra Collaboration Suite, this servlet container is called mailboxd. The mail server includes components:

  • The data store which is a MySQL database that contains all message metadata including tags, negotiation, and pointers to where messages are stored in the file system. Mail IDs are associated with OpenLDAP user accounts.
  • The Message store is the place where all emails are located, including message texts and any file attachments. Messages are stored in MIME format.
  • Index store – index files for each mailbox. The index and search technology are powered by Apache Lucene. Every message is automatically indexed, and every mailbox has an index file associated with it.

Zimbra LDAP – LDAP directory services supply a centralized repository for user and device information allowed on your network. The central repository used for Zimbra LDAP data is the OpenLDAP directory server. Zimbra Collaboration Suite uses OpenLDAP as the open source LDAP directory server. User authentication is provided through OpenLDAP. Each account on the Zimbra server has a unique mailbox ID, which is the primary identification point for the account.

Note that Zimbra also supports integration with Microsoft Active Directory Server.

Zimbra MTA- Postfix-open source Mail Transfer Agent (MTA), which receives mail using SMTP and delivers each message to the desired mailbox of the Zimbra server using the Local Message Delivery Protocol (LMTP). The Zimbra MTA also includes anti-virus and anti-spam components.

Zimbra-SNMP – Zimbra uses a pattern to observe syslog output to generate SNMP traps.

Zimbra Logger – installs tools for syslog aggregation, reporting, useful for viewing server statistics in the admin console.

Please note that if you do not install the logger, in the administration console server statistics section will not be displayed.

Zimbra Spell – This is an open source spelling checker used by the Zimbra web client.

Zimbra Proxy and Zimbra Memcached – These are Zimbra proxy packages.

Zimbra System Directory Tree – Primary directories created by Zimbra installation packages.

Zimbra Desktop – This is a client mail application that can be used as a mail client to any server. You can have the same features using Zimbra Web Access, but, differently from Zimbra Desktop, it works through a browser.

Zimbra Web Clients features:

Below we can see a list of Zimbra web clients features:

  • Create, read, reply, forward and other standard mail functions
  • Viewing mail on the topic of conversation
  • Mail tagging for easy grouping of messages
  • Advanced search and saving of results
  • Calendar
  • Shared calendar, email folders, address books, and portfolio folders
  • Set mailbox preferences, including mail filtering options
  • Using ZCS Documents to Create, Organize and Share Web Documents
  • Using Tasks to Create To-Do Lists and Manage Tasks

Zimbra Administration

Zimbra provides very flexible administration and deployment functionality. The architecture of the software product includes open source development using standard protocols. Third party software is included with Zimbra and is part of the installation process. Zimbra Administration comes with various features:

  • AJAX Web Administration Console.
  • Class of Service (CoS) Management
  • Adding accounts and domains
  • Setting account restrictions, both individual and CoS
  • Creating and editing mailing lists
  • Compatible with Microsoft Exchange 2007/2010.
  • Migration from Microsoft Exchange and Domino.
  • Installing virtual hosts on a domain
  • Server management
  • View and manage system status
  • Monitoring use.

Zimbra Components:

  • Jetty web application server.
  • Postfix, an open-source mail transfer agent (MTA).
  • OpenLDAP, an open source LDAP implementation that provides user authentication.
  • MySQL database.
  • Lucene, an open-source full-featured text search engine
  • Antivirus and antispam open-source components:
  • ClamAV, an antivirus scanner that protects against malicious files
  • SpamAssassin, a mail filter that tries to identify spam
  • Amavisd – new interfaces between the MTA and one or more content validators
  • James / Sieve filtering used to create email filters.


You have several deployment options with Zimbra.

  • Operating Systems: Zimbra runs under Linux, so you can choose your favorite distro, such as Ubuntu, CentOS, RHEL, Oracle
  • Cloud: You can deploy ZCS on a Cloud Service, such as Oracle Cloud, VMware vCloud or Amazon EWS
  • Virtual Machines: You can install and run ZCS also on VMs, like VMWare, VirtualBox and so on

Minimum system requirements: 

Intel / AMD 2.0 GHZ + 8GB Ram, 10GB disk space.

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