Open-Xchange vs Zimbra (2026): which should you pick?

Open-Xchange

• Telcos, ISPs and hosting companies offering branded email to customers
• Governments and public-sector bodies that want sovereign, open-source email
• Organizations replacing Gmail or Outlook at large scale

Zimbra

• Companies and schools that need to keep email on servers they control
• Hosting providers offering white-labeled email to customers
• Teams moving off Microsoft Exchange who want Outlook compatibility

Open-Xchange

• No prices are published; the site directs buyers to book a demo or contact sales.
• The site markets to service providers and the public sector, not individuals or small teams.
• The public-sector page says it is most commonly deployed on-premise.
• OX App Suite is described as open source, but Dovecot Pro, a related product, is a commercial edition.

Zimbra

• Pricing is not published; Zimbra is licensed, and renewals go through an account manager.
• The FAQ calls the Open Source Edition end of life, with no updates or support.
• Features such as backup and restore, Zimbra Office and large-scale mobile sync need the commercial license.
• Chat and real-time collaboration are protected in transit only, not end-to-end encrypted.

Open-Xchange

Email and calendar

A browser interface for email and calendar that the vendor says works the same on desktop, tablet and mobile.

Documents, drive and tasks

Text documents, spreadsheets and presentations in the browser, cloud storage tied to email, and personal and shared tasks.

AI agent

An integrated agent can write emails, schedule appointments, and search, summarize and organize messages, contacts and files.

White-label for providers

Service providers can brand the platform, bundle features and sell tiers, add-ons and upgrades to their own customers.

Deployment choices

Install on-premise, in a public cloud, or use the managed OX Cloud service.

OX Guard encryption

OX Guard provides encrypted email for sensitive communication, which the vendor pitches to regulated professions.

Zimbra

Mail, calendar and contacts

A web client with advanced and attachment search, personal and global address lists, group and resource scheduling, and tasks.

Two editions

Zimbra Daffodil (v10) needs a license, sold as Professional or Standard. Professional has additional features over Standard.

Desktop and mobile access

Zimbra Desktop for Windows, macOS and Linux, a Connector for Outlook on Windows, and ActiveSync on iOS and Android.

Standards-based clients

Works with IMAP, POP, CalDAV and CardDAV, so Thunderbird, Apple Mail and similar clients can connect.

Security and admin controls

Built-in anti-spam and antivirus, two-factor sign-in, LDAP or Active Directory, SAML sign-in and delegated administration.

Deployment options

Install on your own servers, run it in the cloud on AWS or OCI, or use a hosting partner, with multiple domains per install.

Open-Xchange

Pricing could not be confirmed. See ox.io.

Zimbra

Pricing could not be confirmed. See zimbra.com.