Open-Xchange
Open-Xchange is a German open-source software company that builds carrier-grade email and collaboration platforms for telecom operators, hosting providers, and European public-sector organizations seeking a sovereign alternative to Microsoft and Google. Its core product, OX App Suite, is built on Dovecot Pro and sold via subscription, white-label reselling, and managed cloud.
- Company typePrivate
- Founded2005
- HeadquartersKöln, Germany
- Headcount101–250
- GTM typeB2B
- OfferingSoftware
What Open-Xchange does
Open-Xchange (OX) is a German open-source software company founded in 2005 that builds carrier-grade email, calendar, contacts, file sharing, and collaboration infrastructure for two primary customer segments: large telecom operators and hosting providers, and European public-sector organizations pursuing digital sovereignty. Its core product, OX App Suite, is delivered as a white-label, multi-tenant platform that service providers bundle under their own brand with full packaging and pricing control, or that public-sector buyers deploy on-premise for maximum data control; the same platform is also offered as a managed EU-hosted OX Cloud service. The technology is built on Dovecot Pro — the commercial edition of the open-source Dovecot mail server used by over 75% of the world's mail servers — and is complemented by PowerDNS, OX Drive (file sync), OX Documents, and a stack of security add-ons (OX Guard for PGP/S/MIME encryption, OX Advanced Security for phishing/malware defense, and OX Abuse Shield for brute-force and authentication protection). The platform is ISO/IEC 27001:2022 certified and GDPR-compliant, positioning the company as a European sovereign alternative to Microsoft 365 and Google Workspace.
The company monetizes through per-user software subscriptions (monthly for service providers, annual for public sector), managed OX Cloud subscriptions invoiced monthly per provisioned user, optional professional services for implementation and migration, and a revenue-share arrangement with resellers. Distribution runs through direct enterprise and public-sector sales (with prominent "Book a demo" CTAs), a telecom operator/service-provider reseller channel, the openDesk sovereign digital workplace partnership with the German Federal Government's ZenDiS organization, and a ten-party Euro-Office consortium (including IONOS, Nextcloud, and Eurostack) launching a sovereign OnlyOffice-based productivity suite in June 2026. The company operates through wholly owned subsidiaries across Germany (Olpe HQ, Cologne parent, Munich, Stuttgart, Bonn, Hamburg, Karlsruhe), the United States (Palo Alto), France, Italy, Spain, Finland, and Japan, and has raised approximately $67.9 million across five equity rounds since 2006, with the most recent primary round in October 2017. Open-Xchange reports powering "hundreds of millions of user accounts" globally and counts marquee wins such as the German state of Schleswig-Holstein's migration of over 40,000 government mailboxes and 100+ million emails from Microsoft Exchange to OX software.
Open-Xchange firmographics
Firmographics- Name
- Open-Xchange
- Legal name
- Open-Xchange GmbH
- Website
- https://open-xchange.com
- Company type
- Private
- Founded year
- 2005
- Operating status
- Operating
- Headcount range
- 101–250 employees
- Short description
- Open-Xchange is a German open-source software company that builds carrier-grade email and collaboration platforms for telecom operators, hosting providers, and European public-sector organizations seeking a sovereign alternative to Microsoft and Google. Its core product, OX App Suite, is built on Dovecot Pro and sold via subscription, white-label reselling, and managed cloud.
- Ownership category
- akta.pro rank
Open-Xchange industry classification
Industry- Product category
- Email and Collaboration Software
- NAICS
- Software Publishers (5132), Software Publishers (51321)
- SIC
- Services-Prepackaged Software (7372), Services-Computer Programming, Data Processing, Etc. (7370)
- akta.pro primary industry
- Digital Employee Experience (DEX) & IT Experience Management (ITXM) Platforms (HDAEALAL)
Keywords
Where Open-Xchange is headquartered
LocationHeadquarters
- HQ city
- Köln
- HQ country
- Germany
- HQ region
- Europe
Offices14 records
Markets served
Open-Xchange business model
Business model- GTM type
- B2B
- Offering type
- Software
- Cost components
- Technology or R&D, Personnel, Infrastructure, Operations, Marketing or Sales
Revenue model
- Software Licenses and Subscriptions: OX App Suite is offered as subscription-based software with licensing for service providers and public sector organizations. The platform can be deployed on-premise or as managed cloud service, with recurring subscription fees based on provisioned users.
- Cloud Services (OX Cloud): Managed cloud service hosted in the EU (or USA for Open-Xchange Inc customers), with fees invoiced monthly based on number of provisioned users. Revenue share arrangements available for partners reselling the service.
- Professional Services: Consulting services and customer success services available as add-on offerings, including implementation, migration, and ongoing support services.
Pricing tiers
| Model | Billing | Price |
|---|---|---|
| Subscription | Monthly | OX App Suite for Service Providers |
| Subscription | Annual | OX App Suite for Public Sector |
| Subscription | Monthly | OX Cloud Professional/Easy |
Go-to-market motion2 records
Distribution channels4 records
Marketing channels4 records
Open-Xchange product offering
Product offeringCore offering
Open-Xchange develops and licenses OX App Suite, a carrier-grade, open-source email, calendar, contacts, tasks, and file-sharing collaboration platform delivered to telecom operators, hosting providers, and public-sector organizations either as on-premise software or as a managed EU-hosted cloud service (OX Cloud). The portfolio extends to Dovecot Pro (carrier-grade mail server) and PowerDNS (authoritative DNS), together with standalone add-on modules for end-to-end encryption (OX Guard), anti-phishing/malware (OX Advanced Security), and login-abuse prevention (OX Abuse Shield).
Product overview
Open-Xchange offers OX App Suite as its core carrier-grade, open-source email and collaboration platform for service providers and public-sector organizations. The product portfolio includes cloud-hosted OX Cloud (Easy and Professional tiers), and add-on security modules (OX Guard for PGP/SMIME encryption, OX Advanced Security for phishing/malware defense, OX Abuse Shield for login authentication protection). Related OX Group products include Dovecot Pro (email server) and PowerDNS (authoritative DNS). The company partners with openDesk, a sovereign digital workplace platform developed by the German Federal Government's ZenDiS organization. OX Drive provides cross-platform file sync clients, and OX Documents delivers document editing capabilities. All products are built on open-source foundations with a focus on digital sovereignty, data control, and interoperability.
Differentiator
Problem solved
Functional benefit
Brands
- OX App Suite: Open-source email and collaboration platform for service providers and public sector organizations
- Dovecot Pro
- PowerDNS
- OX Abuse Shield
- OX Guard
- OX Cloud
- OX Drive
- OX Documents
Products and services
- OX App Suite Carrier-grade, open-source email, calendar, contacts, tasks, and file-sharing platform sold to telecom operators, hosting providers, and public-sector organizations, deployable on-premise or as a managed cloud service.
- OX Cloud Managed, EU-hosted (or US-hosted for Open-Xchange Inc. customers) cloud version of OX App Suite invoiced monthly per provisioned user, with partner revenue-share arrangements available.
- Dovecot Pro Commercial, carrier-grade IMAP/POP3 mail server product for high-performance email infrastructure at massive scale, sold to service providers and enterprises.
- PowerDNS High-performance authoritative DNS server software for cloud-native platforms, 5G networks, IoT, and encrypted DNS deployments, sold to service providers and enterprises.
- OX Guard Standalone add-on product providing email and file encryption using OpenPGP/S-MIME standards, enabling secure communication with external recipients regardless of their client.
- OX Advanced Security Standalone add-on product providing layered, policy-driven protection against phishing, malware, and advanced email-borne attacks inside the mailbox.
- OX Abuse Shield Standalone add-on product for OX App Suite and Dovecot Pro that blocks brute-force attacks, compromised accounts, suspicious logins, and protocol abuse, with a Lua-scripted policy engine and REST API.
- OX Drive Licensed cross-platform file synchronization and sharing client for Android, iOS, macOS, and Windows that complements OX App Suite storage.
- OX Documents Licensed document editing suite comprising OX Text, OX Spreadsheet, and OX Presentation, with Email Roundtrip for document conversion and GNU GPL v2 backend.
Quantifiable outcome
- Over 40,000 government mailboxes migrated from Microsoft to Open-Xchange in Schleswig-Holstein, Germany
- +2 more outcomes
Companies that use Open-Xchange
Customer profileNamed customers1 record
Segments3 records
Ideal customer profiles3 records
Open-Xchange technology and API
TechnologyTechnology focussed Yes
API detail
- Has API
- No
- API docs
- API detail
Core technology
AI maturity
App detail
AI capability2 records
Feature4 records
Open-Xchange partnerships and signals
Strategic signalPartnerships
Eight partnerships are on record, tiered core and minor.
- openDesk (ZenDiS)coreopenDesk is a sovereign digital workplace platform developed by ZenDiS (Zentrum für Digitale Souveränität der Öffentlichen Verwaltung), a public-sector organization established by the German Federal Government. OX App Suite is integrated into openDesk, providing email and collaboration capabilities. The partnership simplifies procurement for German public authorities as openDesk does not require tender where sovereign digital infrastructure is mandated.
- Euro-Office ConsortiumminorEuro-Office is a European collaborative document-editing solution developed by a consortium including IONOS, Nextcloud, Eurostack, XWiki, OpenProject, Soverin, Abilian, BTactic, OpenXchange, and Office.eu. Launching June 9, 2026 as a sovereign alternative to Microsoft Office and Google Docs, based on OnlyOffice's open-source core.
- Dovecot (OX Group Product)coreOX builds on Dovecot Pro, the industry-standard mail server used by over 75% of the world's mail servers. Dovecot is part of the OX Group product portfolio alongside OX App Suite and PowerDNS, providing carrier-grade email infrastructure at massive scale.
- PowerDNS (OX Group Product)corePowerDNS, Authoritative DNS for Modern, Mission-Critical Networks, is part of the OX Group product portfolio. High-performance DNS software used by service providers and enterprises for secure, fully controlled DNS infrastructure.
- audriga GmbHminorMigration services subcontractor located in Karlsruhe, Germany. Provides data migration services as part of OX deployment projects.
- MicroDoc Computersysteme GmbHminorOX Software Development & Support subcontractor located in Munich, Germany.
- M-Way Solutions GmbHminorOX Software Development & Support subcontractor located in Stuttgart, Germany.
- tarent solutions GmbHminorProfessional Services & Software Development subcontractor located in Bonn, Germany.
Scale indicators5 records
Recent moves6 records
Expansion highlights6 records
Open-Xchange competitors and assessment
Company assessmentDirect peers
- Nextcloud: European open-source collaboration platform offering file sync, groupware, and productivity tools. Direct comparable as an open-source, sovereignty-focused alternative to Microsoft/Google; co-developer in the Euro-Office consortium alongside OX.
- Zimbra (Synacor): Open-source email and collaboration platform serving service providers, governments, and enterprises. Closely comparable product offering (email, calendar, contacts), similar carrier-grade multi-tenant deployments, and overlapping telecom/service-provider customer base.
- IceWarp: Email and team collaboration server offering on-premise and cloud deployment with a focus on Microsoft Exchange replacement. Comparable as a carrier-grade, sovereignty-friendly email/collab platform competing for the same telco and SMB/mid-market replacements.
Broad incumbents
- HCL Domino (formerly IBM Notes/HCL Verse): Established enterprise email, calendaring, and collaboration platform serving large enterprises and governments. Comparable as an on-premise, sovereign-friendly alternative to Microsoft Exchange for regulated and public-sector buyers.
- Microsoft 365 / Exchange Online:
- Google Workspace: Hyperscaler cloud email and productivity suite; named by OX as a primary incumbent alongside Microsoft. Comparable as the second largest target of sovereign displacement campaigns in Europe.
Regional players
- IONOS: European cloud hosting provider that bundles productivity services and is a Euro-Office consortium partner. Comparable as a regional sovereignty-focused platform and channel partner for sovereign email/office offerings in the DACH/EU market.
Emerging players
- Atmail: Email platform provider for service providers and ISPs with webmail and white-label offerings. Comparable as a smaller, niche competitor in the carrier-grade email-for-service-providers segment where OX competes.
- Kolab Systems / MyKolab: Swiss open-source groupware provider targeting privacy-conscious and regulated customers. Comparable as a smaller, open-source, European sovereignty-focused email and collaboration alternative in adjacent segments.
- SmarterMail (SmarterTools): Email server software for businesses and service providers, often deployed as a Microsoft Exchange alternative. Comparable as a competing email-server product targeting similar small/mid-market and hosting-provider customers.
Market position
Strengths4 records
Weaknesses4 records
Competitive moat5 records
Key risks5 records
Key highlights7 records
Customer concentration
Open-Xchange social profiles
Digital presenceOpen-Xchange compliance and trust
Trust signalCompliance2 records
Open-Xchange financial estimates
Financial estimateRevenue estimate
Valuation estimate
Open-Xchange leadership team
Management profileNumber of profiles
Profiles9 records
Open-Xchange subsidiaries and ownership
Company hierarchySubsidiaries9 records
Open-Xchange funding detail
Funding detailFunding overview
Funding rounds5 records
Investors6 records
Funding detail is available on the Subscription and Enterprise plan.Contact sales →
Open-Xchange M&A and investment
M&A and investmentM&A
Investments
M&A and investment is available on the Subscription and Enterprise plan.Contact sales →
Frequently asked questions about Open-Xchange
What does Open-Xchange do?
Open-Xchange develops and licenses OX App Suite, a carrier-grade, open-source email, calendar, contacts, tasks, and file-sharing collaboration platform delivered to telecom operators, hosting providers, and public-sector organizations either as on-premise software or as a managed EU-hosted cloud service (OX Cloud). The portfolio extends to Dovecot Pro (carrier-grade mail server) and PowerDNS (authoritative DNS), together with standalone add-on modules for end-to-end encryption (OX Guard), anti-phishing/malware (OX Advanced Security), and login-abuse prevention (OX Abuse Shield).
Is Open-Xchange a public or private company?
Open-Xchange is a private company. It is classified as venture growth investor backed and is currently operating.
When was Open-Xchange founded?
Open-Xchange was founded in 2005. It employs 101 to 250 people.
Where is Open-Xchange based?
Open-Xchange is headquartered in Köln, Germany, in the Europe region.
How does Open-Xchange make money?
Three revenue lines are on record. Software Licenses and Subscriptions are the primary driver. The others are cloud Services (OX Cloud) and professional Services.
Who are Open-Xchange's main competitors?
Direct peers on record are Nextcloud, Zimbra (Synacor) and IceWarp. Broad incumbents are HCL Domino (formerly IBM Notes/HCL Verse), Microsoft 365 / Exchange Online and Google Workspace. IONOS is listed as a regional player. Emerging players are Atmail, Kolab Systems / MyKolab and SmarterMail (SmarterTools).
Does Open-Xchange have an API?
No public API is recorded for Open-Xchange.
What industry is Open-Xchange in?
Open-Xchange's product category is Email and Collaboration Software. Its primary akta.pro industry code is HDAEALAL, Digital Employee Experience (DEX) & IT Experience Management (ITXM) Platforms. Its NAICS code is 5132 and its SIC code is 7372.