grommunio is a drop-in replacement for Microsoft Exchange — and the perfect migration target when Amazon WorkMail goes dark. Keep Outlook, your workflows, and your data. Gain freedom.
Amazon WorkMail served its purpose. grommunio takes you further — with more protocols, true open source, and no lock-in.
From small businesses to enterprises, grommunio scales with your organization without changing what your team already knows.
Use Outlook, Apple Mail, or any Exchange-compatible client without any reconfiguration. Full MAPI, EWS, and ActiveSync support — natively.
Chat, video conferencing, shared files, and online office editing — all baked in. No third-party plugins, no separate licenses, no fragmented experience.
Self-host on your own infrastructure, on-premises or in any cloud. Your email never passes through a third party. GDPR-compliant by design.
Manage all accounts, configure all applications, and monitor your system from a single secure admin interface. Built for IT teams of any size.
From a team of 5 to an enterprise of 50,000. grommunio's architecture handles high availability, clustering, and multi-domain setups out of the box.
The entire stack — from the groupware backend to the web UI — is open source on GitHub. Audit it, fork it, contribute to it. No black boxes.
grommunio doesn't emulate or translate — it implements these protocols directly in the Gromox backend. That's what makes it a true Exchange drop-in.
Technical details: github.com/grommunio/gromox
grommunio is not a rebranded proprietary system. The full source code — including the Gromox groupware backend — is freely available on GitHub.
The Gromox groupware server implements the Exchange protocols that make grommunio a true drop-in replacement. Inspect every line of code, deploy with confidence.
Amazon WorkMail closes March 31, 2027. Every day you wait is a day less to plan, migrate, and test. Start your grommunio journey today.