Last Updated on February 28, 2026
grommunio is billed as a comprehensive communication and collaboration solution. With open source technology based on Linux, grommunio is scalable and meets the highest security requirements. Thanks to its advanced architecture, grommunio can be integrated into existing systems without great effort.
grommunio runs with just a single user up to many hundreds of thousands of users, from a Raspberry Pi to mainframes or even geo-split installations distributed all over the world.
Gromox is the central groupware server component of grommunio. It is capable of serving as a replacement for Microsoft Exchange and compatibles. Connectivity options include RPC/HTTP (Outlook Anywhere), MAPI/HTTP, EWS, IMAP, POP3, an SMTP-speaking LDA, and a PHP module with a MAPI function subset. Components can scale-out over multiple hosts.
This is free and open source software.
Key Features
- Emails, contacts, calendars in one platform – with integrated enterprise-grade Active Sync, your data is available on all devices in real time.
- Organize projects with shared folders and create schedules to see at a glance when your colleagues have time.
- Calendar – edit entries however is most convenient for you. grommunio syncs calendars on all devices simultaneously. grommunio syncs calendars on all devices simultaneously.
- Office suite.
- Enterprise-grade security.
- Appliance offers a wide range of interfaces … for optimal integration in a variety of environments.
- Individual and group messages, file sharing and search
- Unlimited search history.
- Multilingual translation.
- Emoji, GIF and Markdown support.
- Enterprise-grade security, availability and scalability.
- Secure with ID-only mobile push notifications.
- Multi-factor authentication.
- Cross-platform support – runs under Linux, macOS, Android, and Windows.
Website: grommunio.co
Support: GitHub Code Repository
Developer: grommunio
License: GNU Affero General Public License v3.0
Gromox is written in C++. Learn C++ with our recommended free books and free tutorials.
Related Software
| Groupware Software | |
|---|---|
| Zimbra | Full-featured collaboration suite |
| SOGo | Collaborative software server focusing on simplicity and scalability |
| Kolab | Secure, scalable, and reliable groupware server |
| eGroupware | Enterprise ready web-based groupware suite |
| OpenMeetings | Video conferencing, instant messaging, whiteboard, and other groupware |
| Citadel | Complete and feature-rich groupware server |
| Kopano | Groupware application suite originally based on Zarafa |
| grommunio | Modern, digital communication and collaboration |
| HordeGroupware | Popular full-featured groupware server |
Read our verdict in the software roundup.
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