Is Zimbra Free? The Complete 2026 Guide to Zimbra Open Source Edition

Key Takeaways: Zimbra Free (Open Source Edition) is real, but official free binaries were discontinued at version 8.8.15. Since version 9, you must build from source or use community-maintained FOSS builds (UALinux, TechFiles.online). The free edition includes email, calendar, contacts, antispam, antivirus, and webmail — but NOT ActiveSync for mobile. Zimbra Free supports unlimited users; performance depends on your server hardware. Security is critical: CVE-2024-45519 (2024 RCE vulnerability) affects unpatched Zimbra installs — always use current builds.

Zimbra Free is one of the most searched questions among sysadmins and business owners evaluating open-source email infrastructure — and the answer is more nuanced than a simple yes or no. Yes, Zimbra is free: the Zimbra Collaboration Suite (ZCS) Open Source Edition (OSE) has been available under an open-source license since 2005. However, starting with version 9, Zimbra ceased distributing official free binary builds. Today, in 2025, getting Zimbra for free requires either building from the official zm-build GitHub repository or downloading from trusted community-maintained FOSS build projects.

This comprehensive guide answers every question about Zimbra Free: what it includes, what it does not include, how to get it in 2025, how to install it on Ubuntu 22.04 or AlmaLinux 9, and how it compares against the paid Network Edition and top open-source alternatives like Carbonio CE and iRedMail. By the end of this article, you will know exactly whether Zimbra Free is the right choice for your organization — and precisely how to get it running.

1.  What Is Zimbra Free? (Zimbra Collaboration Suite Overview)

The Zimbra Collaboration Suite (ZCS) is a full-featured, open-source email server and collaboration platform that combines email, calendar, contacts, task management, file sharing, instant messaging, and an AJAX-powered webmail client into a single self-hosted solution. It is architecturally comparable to Microsoft Exchange Server or Google Workspace — but with the critical advantage that it runs entirely on your own Linux server at zero licensing cost in its Open Source Edition.

Zimbra was originally developed by LiquidSys, which renamed itself Zimbra, Inc. in 2005. The platform has since passed through several corporate owners: Yahoo! acquired it in 2007, sold it to VMware in 2010, which sold it to Telligent Systems in 2013 (soon rebranded as Zimbra, Inc.), which was then acquired by Synacor in 2015. This turbulent ownership history caused some confusion around support commitments, but Zimbra itself remained robust and actively developed throughout.

Two core editions of Zimbra exist: the Open Source Edition (OSE/FOSS) — which is free — and the Network Edition (NE) — which is paid and adds enterprise features like ActiveSync mobile support and an Outlook connector. The most recent major release is Zimbra Daffodil (version 10.1), which supports Ubuntu 20.04/22.04, RHEL 8/9, AlmaLinux 8/9, and Rocky Linux 8/9 as of 2025.

As an open-source email server, Zimbra is built on a stack of trusted open-source components: Postfix (MTA), MariaDB (database), OpenLDAP (directory services), Nginx (reverse proxy), Jetty (application server), Lucene (search indexing), ClamAV (antivirus), SpamAssassin (anti-spam), and OpenDKIM (email authentication). This mature, battle-tested stack is part of what makes Zimbra a leading choice for self-hosted email and on-premises deployment scenarios.

2.  Is Zimbra Really Free? The Complete 2025 Truth

This is the question that generates the most confusion. Short answer: yes, Zimbra is free to use — but getting it requires extra steps in 2025. Here is the full picture.

2.1  Zimbra Was Free Until Version 9

Up through version 8.8.15 GA (the last freely available binary release), Zimbra published official, ready-to-install binary packages for the Open Source Edition. You could simply download a .tgz file from files.zimbra.com and run the installer. Millions of organizations worldwide used this path.

Starting with version 9.0.0, Zimbra made a strategic pivot: the source code remained open-source and available on GitHub (github.com/zimbra/zm-build), but Zimbra ceased distributing free official binary packages. On their own FAQ page, Zimbra states: “Zimbra continues to maintain most of its products as a full open-source initiative. The binaries, however, will no longer be free to download and use.”

This change caught many administrators off guard — and is the source of the widespread “Is Zimbra Free?” confusion that still surfaces in search results today. The code is open. The precompiled installer is not freely offered by Zimbra itself anymore.

⚠️  Important Warning: ZCS 8.8.15 reached end-of-life status. Running it in production in 2025 exposes your organization to unpatched security vulnerabilities, including CVE-2024-45519.Do NOT use version 8.8.15 on a production server. Use a current community FOSS build of version 10.1.x instead.

2.2  How to Get Zimbra Free Today (2025)

There are three legitimate paths to running Zimbra for free today. Each suits different technical skill levels and operational contexts:

1. Build from source (GitHub).  Clone the official zimbra/zm-build repository and follow the build instructions. This requires a build server with 16+ GB RAM and a supported Linux distribution. Suitable for teams who want to track every change.
2. UALinux free OSE 10 builds.  The UALinux team (ualinux.com/en/zimbra) compiles ready-to-use Zimbra 10 OSE packages from the official source. Free to download after registration. Updated regularly with security patches.
3. TechFiles.online FOSS builds.  Community contributor Ian Walker publishes quarterly FOSS builds at techfiles.online/zimbra. Builds are available for Ubuntu 22.04, AlmaLinux 8/9, Rocky Linux 8/9, and RHEL 8/9. SHA256 checksums are provided. The latest build as of early 2026 is version 10.1.15.

💡  Pro Tip: For most organizations, the TechFiles.online or UALinux community builds are the best starting point — they are built from the same official source code, updated quarterly, and include current security patches. Verify every download using SHA256: sha256sum -c <filename>.sha256

2.3  What the Zimbra Free License Covers

Zimbra OSE is dual-licensed under: GPL v2 (server backend components) and CPAL v1 — Common Public Attribution License (the Zimbra web client frontend). Both licenses permit commercial use.

• Free for both commercial and non-commercial use — no per-user fees, no seat limits
• Branding restrictions apply — you may not remove or replace the Zimbra trademark in the user interface
• No official support included — community forums at forums.zimbra.org are your primary resource
• Source code modifications are permitted and encouraged under the GPL v2 terms

3.  Zimbra Free Features: What You Get for Nothing

Zimbra Open Source Edition is remarkably feature-complete. Despite being the free tier, it includes a comprehensive email collaboration platform that rivals many paid solutions. Here is everything included at no cost:

• AJAX-powered webmail client — HTML5, fast, supports drag-and-drop, right-click menus, keyboard shortcuts
• IMAP / POP3 / SMTP server — full protocol support via Postfix MTA; connects to Thunderbird, Apple Mail, and other clients
• Shared group calendars (CalDAV) — create, share, and co-edit calendars across your organization
• Contact management (CardDAV) — global address book, personal contacts, distribution lists
• Tasks and notes — built-in productivity tools integrated with the webmail interface
• Document sharing — share files within conversations and folders
• Anti-spam filtering — SpamAssassin and DSPAM scan every inbound message; automated spam training with ham/spam users
• Antivirus protection — ClamAV integration via Amavis scans all inbound and outbound email
• OpenLDAP directory — manage user accounts, groups, and authentication; external Active Directory authentication also supported
• Multi-domain support — host unlimited email domains on a single Zimbra server instance
• Admin console (port 7071) — browser-based administration for user management, domain configuration, server monitoring
• Zimlets — plugin/mashup extension framework allowing integration with third-party services
• Mobile browser access — responsive webmail works on smartphones via any browser
• S/MIME email signing and encryption — available in OSE for organizations requiring signed/encrypted email
• MariaDB storage backend — stores email metadata, account settings; Lucene provides full-text search indexing
• Nginx reverse proxy — handles HTTPS termination, IMAP/POP3 proxy, load balancing
• OpenDKIM — DKIM key generation and email signing for outbound mail authentication

📌 Note: What is NOT included in the free edition is just as important as what is included.ActiveSync for native iPhone/Android sync is PAID-ONLY. This is the single most common surprise for new Zimbra users. The Outlook MAPI/EWS connector is PAID-ONLY. Free users can connect Outlook via IMAP, but will lose calendar and contact sync.

4.  Zimbra Free vs Paid Network Edition: Key Differences

Understanding the boundary between the free Open Source Edition and the paid Network Edition is critical before committing to a deployment. The table below covers every major feature decision point between Zimbra open source vs paid tiers:

Feature	Free OSE	Paid Network Edition
Webmail client (AJAX)	✅ Included	✅ Included
IMAP / POP3 / SMTP	✅ Included	✅ Included
Calendar (CalDAV)	✅ Included	✅ Included
Contacts (CardDAV)	✅ Included	✅ Included
Anti-spam (SpamAssassin)	✅ Included	✅ Included
Antivirus (ClamAV)	✅ Included	✅ Included
Multi-domain support	✅ Included	✅ Included
S/MIME encryption	✅ Included	✅ Included
Unlimited user accounts	✅ Included	✅ Included
Admin console (port 7071)	✅ Included	✅ Included
ActiveSync (mobile sync)	❌ Not available	✅ Professional tier
Outlook MAPI connector	❌ Not available	✅ Professional tier
Built-in backup & restore	❌ Not available	✅ Both tiers
Archiving & eDiscovery	❌ Not available	✅ Both tiers
Mailbox migration tools	❌ Not available	✅ Both tiers
Official Zimbra support	❌ Community only	✅ Both tiers
High-availability clustering	⚠️ Limited	✅ Full HA support
HSM (tiered storage)	❌ Not available	✅ Both tiers

⚠️  Important WarningActiveSync is NOT available in the free edition. This means iPhone, Android, and native Outlook users cannot sync their calendar and contacts to Zimbra without a paid license or third-party solution like Z-Push (an open-source ActiveSync implementation).If mobile calendar and contact sync is a business requirement, factor in either the Network Edition cost or a Z-Push implementation effort before committing to OSE.

For many organizations — especially those with 50–500 users comfortable with browser-based webmail — the free OSE covers 90% of what they need. The paid upgrade makes sense primarily when native mobile sync or Outlook calendar/contact integration is required.

Also Read: Nimbuskz Email Client

5.  Zimbra Free System Requirements (2025 Updated)

Accurate Zimbra free system requirements for 2025 are critical because most guides online still reference outdated Ubuntu 18.04 or hardware specs from version 8. The following requirements apply to Zimbra 10.1.x community builds:

5.1  Minimum Hardware Requirements

• RAM: 8 GB minimum — 16 GB strongly recommended for 50+ active users; 32 GB for 200+ users
• CPU: 4-core 64-bit processor (x86_64 only — ARM is not supported)
• Storage: 10 GB minimum for the Zimbra installation itself; add adequate space for mail storage (plan ~2–5 GB per active user)
• Swap: At least 4 GB swap space configured
• Supported OS: Ubuntu 20.04 LTS or 22.04 LTS (64-bit), RHEL 8/9, AlmaLinux 8/9, Rocky Linux 8/9
• Fresh installation required: Do not install Zimbra on a server already running Postfix, Apache, or another LDAP server — conflicts will break the installer

💡  Pro Tip: For a production deployment, use Ubuntu 22.04 LTS or AlmaLinux 9. Both are fully supported by current community builds and will receive security updates through 2027+.Provision storage with room to grow. Zimbra mail storage grows over time, and running out of disk space will corrupt the mail queue. Use LVM or a cloud storage volume that can be expanded.

5.2  Network Prerequisites

Zimbra requires a correctly configured network environment. Missing any of these will result in email delivery failures or a broken installation:

• Static IP address — essential for consistent DNS resolution and deliverability
• Fully Qualified Domain Name (FQDN) — your server must have a hostname like mail.yourdomain.com that resolves in DNS
• A record — DNS A record for mail.yourdomain.com pointing to your server’s public IP
• MX record — DNS MX record for yourdomain.com pointing to mail.yourdomain.com
• PTR (reverse DNS) record — required for email deliverability; configure with your VPS/hosting provider
• Open firewall ports — see table below

Port	Protocol	Purpose
25	SMTP	Email delivery (inbound/outbound)
110	POP3	Legacy email client retrieval
143	IMAP	Email access (modern clients)
443	HTTPS	Webmail client + admin HTTPS
465	SMTPS	Authenticated SMTP over SSL
587	Submission	Client email submission (recommended)
993	IMAPS	IMAP over SSL/TLS
995	POP3S	POP3 over SSL/TLS
7071	HTTPS	Zimbra Admin Console

6.  How to Install Zimbra Free in 2025: Step-by-Step Guide

The following steps walk you through a complete how-to install Zimbra free on Ubuntu 22.04 production deployment using the TechFiles online community build. The same process applies to AlmaLinux 9 with minor package manager substitutions (dnf instead of apt).

Step 1 — Download the Free Zimbra Build

Visit techfiles.online/zimbra (TechFiles) or ualinux.com/en/zimbra (UALinux) and download the appropriate build for your OS. For Ubuntu 22.04, download the UBUNTU22_64 .tgz file. Always verify the download with SHA256:

# Download the latest Zimbra 10.1.x FOSS build for Ubuntu 22.04

wget https://cdn.techfiles.online/ubuntu/zcs-10.1.15_GA_0126.UBUNTU22_64.20260105193411.tgz

# Verify the SHA256 checksum

sha256sum -c zcs-10.1.15_GA_0126.UBUNTU22_64.20260105193411.tgz.sha256

# Expected output: <filename>: OK

Step 2 — Prepare Your Linux Server

A clean Ubuntu 22.04 server with no pre-existing mail services is required. Run the following preparation steps:

# Update all system packages

sudo apt update && sudo apt upgrade -y

# Install required dependencies

sudo apt install -y wget curl netcat-openbsd perl unzip pax libgmp-dev

# Set your server hostname (FQDN)

sudo hostnamectl set-hostname mail.yourdomain.com

# Add FQDN to /etc/hosts

# Edit /etc/hosts and add this line (replace 1.2.3.4 with your public IP):

# 1.2.3.4   mail.yourdomain.com   mail

# Install and configure dnsmasq (local DNS resolver required by Zimbra)

sudo apt install -y dnsmasq

sudo systemctl disable systemd-resolved

sudo systemctl stop systemd-resolved

# Configure dnsmasq (/etc/dnsmasq.conf) with your MX and A records

# server=8.8.8.8

# domain=yourdomain.com

# mx-host=yourdomain.com, mail.yourdomain.com,5

# listen-address=127.0.0.1

sudo systemctl restart dnsmasq

Step 3 — Run the Zimbra Installer

# Extract the downloaded archive

tar -xzf zcs-10.1.15_GA_0126.UBUNTU22_64.20260105193411.tgz

cd zcs-10.1.15_GA_0126.UBUNTU22_64.20260105193411

# Run the installer as root

sudo ./install.sh

# When prompted, accept the license agreement: y

# Use Zimbra’s package repository: y

# Select packages to install (recommended for single-server setup):

# zimbra-ldap:       y

# zimbra-logger:     y

# zimbra-mta:        y

# zimbra-dnscache:   n  (using dnsmasq instead)

# zimbra-snmp:       y

# zimbra-store:      y

# zimbra-apache:     y

# zimbra-spell:      y

# zimbra-memcached:  y

# zimbra-proxy:      y

# In the configuration menu, navigate to zimbra-store > Admin Password

# Set a strong admin password when prompted

# Apply all settings and wait for installation to complete (5-15 minutes)

Step 4 — Post-Installation Configuration

Once installation completes, access the Zimbra Admin Console at https://mail.yourdomain.com:7071 with username admin and the password you set during installation.

# Switch to the Zimbra service user for post-install commands

sudo su – zimbra

# Configure SSL/TLS with Let’s Encrypt (run as zimbra user)

# First obtain your certificate, then deploy it:

/opt/zimbra/bin/zmcertmgr deploycrt comm /path/to/cert.pem /path/to/ca-bundle.pem

# Enable DKIM signing for your domain

/opt/zimbra/libexec/zmdkimkeyutil -a -d yourdomain.com

# DKIM public key will be displayed — add it as a TXT record in your DNS

# Format: <selector>._domainkey.yourdomain.com  IN  TXT  “v=DKIM1; k=rsa; p=<pubkey>”

# Verify Zimbra services are running

zmcontrol status

# Restart all services if needed

zmcontrol restart

Also configure in the Admin Console:

• Class of Service (COS): Set default quotas, features, and interface options for user accounts
• SPF record: Add a TXT record: v=spf1 mx a ip4:YOUR_IP ~all
• DMARC record: Add a TXT record for _dmarc.yourdomain.com: v=DMARC1; p=quarantine; rua=mailto:dmarc@yourdomain.com
• Two-factor authentication: Enable 2FA for all admin accounts via Admin Console → Manage → Security

💡  Pro Tip: After installation, send a test email to a Gmail address and use Google’s email header analysis to confirm DKIM, SPF, and DMARC all pass. Use mail-tester.com to check your server’s overall spam score before going live. Aim for a score of 9/10 or above.

7.  Zimbra Free for Specific Use Cases

7.1  Zimbra Free for Small Businesses

Zimbra Free is an excellent free email server for small businesses that want full control over their email infrastructure without paying per-user SaaS fees. A small business with 25–200 employees can run a complete, self-hosted email and collaboration platform on a $40–$80/month VPS or dedicated server. With no seat licensing, the math is compelling: Google Workspace at $6/user/month costs $1,800/year for 25 users; Zimbra Free costs only your server rental.

The key consideration is IT capacity. Zimbra requires an administrator comfortable with Linux server management. If your organization lacks in-house Linux skills, consider a managed hosting partner or evaluate Carbonio CE (see Section 8).

7.2  Zimbra Free for Universities and Educational Institutions

Zimbra has long been popular in higher education. Its support for unlimited users, LDAP/Active Directory integration, and CalDAV group calendar sharing make it ideal for university deployments where hundreds or thousands of students and faculty need email accounts. Many universities have used Zimbra OSE 8.8.15 for years; those institutions should migrate to the current 10.1.x community built to maintain security.

For educational institutions, data sovereignty is a major advantage: student email data stays on institution-controlled servers, avoiding FERPA compliance issues associated with third-party cloud providers. There is no per-user licensing cost regardless of enrollment size.

7.3  Zimbra Free for Nonprofits

Nonprofits operating on tight budgets frequently choose Zimbra Free to eliminate email licensing costs entirely. The combination of zero licensing fees, unlimited user accounts, built-in anti-spam, and a professional webmail interface makes Zimbra OSE a natural fit. A Zimbra installation on a $50/month VPS handles the email needs of a 100-person nonprofit with no ongoing software costs.

7.4  Zimbra Free for Government and Healthcare (Data Sovereignty)

Government agencies and healthcare organizations subject to strict data sovereignty and compliance requirements (GDPR in Europe, HIPAA in the US, sovereign cloud mandates in various countries) often cannot use cloud email services at all. Zimbra’s on-premises deployment model — where every byte of email data lives on infrastructure you own and control — satisfies these requirements directly.

Notably, Zimbra’s S/MIME support in the free edition enables organizations to digitally sign and encrypt email without additional licensing costs — a requirement in many regulated industries. The LDAP integration with existing Active Directory deployments further reduces migration friction for government IT environments.

8.  Top Free Zimbra Alternatives in 2025

Whether you decide Zimbra is not the right fit or simply want to compare your options, here are the top free Zimbra alternatives in 2025 — a comparison that no current top-ranking competitor article covers comprehensively:

Solution	Best For	Key Advantage	Free?
Carbonio CE (Zextras)	Zimbra OSE migrants	Modern UI, active development, direct OSE successor	✅ FOSS
iRedMail	Lightweight installs	One-command install, minimal resources, solid docs	✅ Open Source
Mailcow	Docker deployments	Modern admin UI, easy updates, active community	✅ Open Source
Roundcube + Stack	DIY sysadmins	Total control, modular, widely understood components	✅ Open Source
SOGo	CalDAV/CardDAV focus	Excellent calendar/contact sync, ActiveSync in free tier	✅ Open Source

Carbonio Community Edition (CE)

Developed by Zextras, Carbonio CE is arguably the most important Zimbra alternative in 2025 because it is a direct architectural successor to Zimbra OSE. Carbonio CE supports the same LDAP/SMTP/IMAP/CalDAV stack, runs on the same hardware profile, and offers a migration path from Zimbra OSE with minimal retraining. Critically, it includes ActiveSync in the free community edition — solving the single biggest limitation of Zimbra Free. For organizations that need mobile sync without paying for Zimbra Network Edition, Carbonio CE is worth serious evaluation.

iRedMail

iRedMail is a lightweight, fast-deploying open-source mail server that combines Postfix, Dovecot, Roundcube, and SOGo into a coherent stack. A complete mail server can be deployed in under 30 minutes. iRedMail lacks Zimbra’s rich admin console and Zimlet extensibility, but is an excellent choice for smaller organizations or those who want a simpler footprint. A free admin panel (iRedAdmin) is included; a more capable paid admin panel is optionally available.

Mailcow: dockerized

Mailcow is a Docker-based mail server suite built on Postfix, Dovecot, SOGo, and Rspamd. Its modern web UI makes administration significantly more approachable than Zimbra’s admin console, and Docker-based deployment simplifies backups and migrations. Mailcow is actively maintained and popular with technically-inclined small teams and hosting providers. It does not match Zimbra’s enterprise feature depth for large organizations.

9.  Zimbra Free Security: CVE-2024-45519 & Best Practices

Security is a non-negotiable concern for any email server. In 2024, Zimbra was struck by a significant and widely-exploited vulnerability: CVE-2024-45519, a Remote Code Execution (RCE) vulnerability in Zimbra’s postjournal service. Attackers could send specially crafted emails that triggered remote command execution on the affected Zimbra server — no authentication required.

The vulnerability affected Zimbra versions 9.0.0 and 10.0.x. Zimbra released patches in versions 9.0.0 patch 41 and 10.0.9. The current community builds (10.1.x from TechFiles.online and UALinux) include fixes for this vulnerability.

This is precisely why running the legacy version 8.8.15 in 2025 is dangerous: it cannot receive the CVE-2024-45519 patch and likely contains additional unaddressed vulnerabilities. Any organization still running ZCS 8.8.15 must migrate to 10.1.x immediately.

Security Hardening Checklist for Zimbra Free

• Use current builds: Always run the latest 10.1.x community build — update at least quarterly
• Disable postjournal if unused: zmprov mcf zimbraPostJournalEnabled FALSE
• Enable firewall: Restrict port 7071 (Admin Console) to trusted IPs only using UFW or iptables
• Enforce SSL/TLS: Use a valid certificate (Let’s Encrypt is free); never run production Zimbra with self-signed certs
• Implement DKIM + SPF + DMARC: Protects your domain from spoofing and improves inbox deliverability
• Enable 2FA: Required for all administrator accounts to prevent credential-based compromise
• Monitor logs: Zimbra logs are in /opt/zimbra/log/ — set up log monitoring for anomalous authentication attempts
• Patch immediately: Subscribe to Zimbra security advisories at zimbra.com and apply community build updates within 72 hours of critical patches

💡  Pro Tip: Use Fail2ban to block repeated failed Zimbra login attempts. Community-maintained Zimbra Fail2ban configuration files are available on GitHub.Run regular port scans against your Zimbra server using nmap to verify that only the intended ports are exposed to the public internet.

10.  Frequently Asked Questions About Zimbra Free

Q: Is Zimbra completely free?

A: Zimbra Open Source Edition is free to use — the code is licensed under GPL v2 and CPAL v1. However, since version 9, Zimbra no longer distributes official free binary installers. To run Zimbra for free today, you must either build it from source (github.com/zimbra/zm-build) or download a community FOSS build from TechFiles.online or UALinux. Both options are free and fully legitimate.

Q: What is the difference between Zimbra Open Source and Network Edition?

A: The key differences are in enterprise features: the Network Edition adds ActiveSync (for native mobile email/calendar/contact sync on iPhone and Android), the Outlook MAPI connector (for full calendar and contact sync in Microsoft Outlook), built-in backup & restore, archiving & eDiscovery tools, and official Zimbra support. The free OSE includes full email, calendar, contacts, anti-spam, antivirus, admin console, and S/MIME — but not ActiveSync or the Outlook connector.

Q: Can I use Zimbra free for commercial purposes?

A: Yes. The GPL v2 and CPAL v1 licenses both explicitly permit commercial use. You may use Zimbra OSE to run email for a commercial business with no licensing fees. The only restriction is branding — you may not remove the Zimbra trademark from the user interface.

Q: How many users can Zimbra Free support?

A: There is no user limit in the Open Source Edition. The number of users your Zimbra server can support depends entirely on your hardware: a server with 8 GB RAM comfortably handles 50–200 active users; 16 GB RAM supports 200–500 users; 32 GB RAM supports 500–2,000+ users.

Q: Is Zimbra Free still actively maintained in 2025?

A: Yes. The Zimbra source code is actively maintained on GitHub at github.com/zimbra/zm-build. Community-built providers (TechFiles.online, UALinux) publish updated builds quarterly that include security patches. The latest stable version as of early 2026 is 10.1.15.

Q: What is Zimbra Daffodil v10?

A: Zimbra Daffodil (version 10 and 10.1) is the current major release of Zimbra. It requires a license file for official Zimbra-distributed binaries. However, free community builds of Daffodil (v10.1.x) are available from TechFiles.online and UALinux without a license requirement.

Q: Does Zimbra Free include antispam and antivirus?

A: Yes. Zimbra OSE includes SpamAssassin for spam filtering, DSPAM for Bayesian spam learning, and ClamAV for antivirus scanning (via Amavis integration). All three are enabled by default and run automatically on every inbound message.

Q: Is Zimbra Free GDPR compliant?

A: Self-hosted Zimbra gives you complete control over where email data is stored and processed, making it inherently more GDPR-friendly than cloud email services. GDPR compliance depends on your organizational practices (data retention policies, access controls, breach notification procedures), not just the software. Zimbra OSE provides all the technical controls needed to build a GDPR-compliant email environment.

Q: Can I use Z-Push to add ActiveSync to Zimbra Free?

A: Yes. Z-Push is an open-source ActiveSync implementation that can be installed alongside Zimbra OSE to provide native mobile sync for iPhone and Android devices. This is the most common workaround for OSE’s lack of built-in ActiveSync. Z-Push requires additional setup and maintenance but is a viable free alternative to upgrading to Network Edition for organizations that only need mobile sync.

11.  Conclusion: Should You Use Zimbra Free in 2025?

The answer depends on your specific requirements. Zimbra Free — via community OSE builds — remains one of the most capable and mature open-source email collaboration platforms available anywhere. For the right use case, it is an excellent choice that saves thousands of dollars annually compared to paid cloud alternatives.

Choose Zimbra Free if:

• You are managing 50 to 5,000 users on Linux-based infrastructure
• Data sovereignty is a requirement — your organization must keep email on premises
• You are a university, nonprofit, government agency, or budget-conscious SMB
• Your users are comfortable with browser-based webmail (no native Outlook or mobile sync needed)
• You want to eliminate per-seat email licensing costs permanently
• Your IT team has Linux administration skills

Consider the paid Network Edition or Carbonio CE if:

• Native mobile ActiveSync (iPhone/Android calendar and contact sync) is a firm requirement
• Your users rely heavily on Microsoft Outlook with calendar and contact sync
• You need official vendor support with an SLA
• Built-in enterprise backup/restore and eDiscovery tools are required

The best path forward: start with a TechFiles.online or UALinux community build of Zimbra 10.1.x on Ubuntu 22.04 LTS or AlmaLinux 9. Follow the step-by-step installation guide in Section 6 of this article, implement all security hardening steps in Section 9, and you will have a production-ready, free enterprise email server running within a few hours.