• The next generation
  • Open Source communication 
  • and collaboration enterprise solution!



An enterprise ready email, calendar and collaboration solution built for the cloud (both public and private)
The best Open Source solution for your organization to lower IT costs while leveraging effective communication and fostering collaboration
A proven success story with more than 1,000,000 mailboxes running across major public institutions and private corporations around the world

OBM's continued growth since it's first release

OBM Features

Robust and easy-to-use Webmail

The sleek interface brings together email, contacts, calendar, and instant messaging all in one place. Increase efficiency with intuitive functionality such as drag-and-drop attachments and autosaved drafts.

Access your messages anywhere, anytime and on any device

IMAP synchronization provides the same powerful OBM experience online and offline across all the major mobile, webmail, and desktop email clients.

Protect your organization with ultra high security

Secured back-ups, integrated anti-spam and anti-virus as well as SSO authentication. Configurable cross mailbox discovery and archiving for regulatory compliance.


A calendar designed for the enterprise

Have complete flexibility to create, manage and share individual, group and resource calendars. Easily set up events with a high level of customization including privacy settings, reminders, recurrences and attachments.

Always know where you need to be

Sync your calendar across all major mobile devices and apps, desktop clients, and Microsoft Exchange. Share and receive calendar events with ICS files and iCal support.


Quickly find the right person with a rich contact system

Saving and searching for contacts is made simple with enhanced features such as auto-info collecting functionality, multi-addressbook support and shared distribution lists.

Get the latest information on all your contacts

Sync your contact list across all major mobile devices and desktop clients. Organize your addressbook’s information fields to best fit your needs.

All the tools for productive and secure online meetings

Built-in smart webconferencing allows you to bring together anyone from inside and outside your organization while supporting private and group chats, document and screen sharing, and sketch tools to highlight any shared document or application. If anyone can’t make the meeting then just click record!

Easy web-based administration

Manage end-user features, quotas, storage policies via Class-of-Service (CoS) and from anywhere using the secure and centralized web-based Administration. Determine the right level of security for users with SSO, CAS, SAML, and smartcard authentication, while also configuring mailbox backups and restores using hierarchical storage management (HSM).

Protect your organization by deploying OBM on premise or on the cloud

OBM can be run natively on hardware or virtualized architecture, and fully supports multi-tenancy and delegated administration for hosting and service providers.

License and Business Model

We love REAL "Open Source" software, meaning it is Libre & Free

Libre (Free in French) – Anyone has the ability to use and develop upon OBM however they would like.

Free – The software and license are 100% free of charge to download and use at any time.

And that is why OBM is a Libre & Free software.

Our Licenses

The OBM license is an official GNU Affero General Public License version 3.

OBM: AGPL v3 with additional terms.

Thunderbird connector: AGPLv3 with additional terms.

Our Services

To make sure your organization has the highest level of security and productivity, we offer technical support contracts for purchase that cover everything and anything from deployment planning to hands-on optimization.

OBM’s technical support team works in tandem with the R&D team in order to help customers remain updated on system enhancements while simultaneously contributing to OBM’s continual development and evolution.


OBM.org: Community website

Download OBM & tools


OBM Technical Support Services provide direct access to our expert OBM Support engineers who are ready to assist you in the development, deployment, and management of OBM installations.

StandardBasic support, not intended for high-visibility production platforms. PremiumFor production platforms with priority assistance and access to our R&D team.OSSAIdeal for high-visibility production platforms with top priority assistance 24x7. 

Customer stories

OBM Ecosystem