grommunio is unclaimed —

grommunio

The native Exchange drop-in replacement. As sovereign as you.·grommunio.com

grommunio is a European, open-source groupware and collaboration platform covering email, calendar, contacts, chat, video and file sharing. It implements native Exchange protocols (MAPI/HTTP, EWS, Exchange ActiveSync) alongside open standards (IMAP, POP3, SMTP, CalDAV, CardDAV, LDAP), letting organizations keep using existing clients like Microsoft Outlook and Apple Mail. It can be deployed on-premises, in a private cloud, or through certified hosting partners, giving organizations full control over their infrastructure and data.

What it's for

Replacing Microsoft Exchange with a self-hosted, Outlook-compatible mail serverTeam scheduling with shared calendars and free/busy lookupSecure video meetings and screen sharingEnterprise chat with file sharingReal-time collaborative document editingCompliant email archiving for legal and audit purposesMobile device management for company devicesMigrating mailboxes from Microsoft Exchange or IMAP servers

Features 19

Browser-based video meetings (grommunio Meet) with WebRTC, screen sharing and moderation
Centralized, browser-based Admin UI for user, group, domain and server management
Compliant email archiving (grommunio Archive) with search, encryption, 2FA and audit logs
Enterprise chat (grommunio Chat) with 1:1/group messaging, file sharing and workflow integrations
Full contact management with groups, multiple folders and vCard export
Full multi-tenancy and delegated administration
IMAP, POP3, SMTP, CalDAV, CardDAV and LDAP support
Migration tools from Microsoft Exchange (PST import) and IMAP servers
Mobile Device Management (MDM) with remote wipe and policy enforcement
Multi-factor authentication, OIDC, SAML 2.0 and LDAP/Active Directory integration
Native Outlook compatibility via MAPI/HTTP, EWS and Exchange ActiveSync, no plugins required
Real-time collaborative document editing (grommunio Office via OnlyOffice) for DOCX, XLSX, PPTX, ODF
Recurring events with custom exceptions
S/MIME signing and encryption
Secure file sharing and sync (grommunio Files) with passwords and expiry dates
Shared calendars with Free/Busy time suggestions and delegation
Shared mailboxes, public folders and global address lists
Spam and malware protection via grommunio-antispam (Rspamd) and ClamAV
Task and note management with categories, flags, reminders and time tracking

At a glance

free tierfree trialopen sourceself-hostableAPI

TypeWeb app

DeploymentSelf-hosted

PlatformsWeb, Windows, macOS, Linux, iOS, Android

LanguagesEnglish, German, French, Italian, Spanish, Portuguese, Portuguese (Brazil), Dutch, Swedish, Norwegian, Finnish, Polish, Czech, Chinese, Japanese

Forpublic administrations, healthcare organizations, educational institutions, financial service providers, companies with high compliance and data protection requirements, mid-sized enterprises, international corporations, managed service providers, cloud hosters

Companygrommunio GmbH · 2020

Integrations

OnlyOfficeRspamdClamAVMicrosoft OutlookApple MailLDAPActive Directory

Complianceself-reported

GDPRCCPAePrivacy

Resources

Pricing

Paid tiers are priced per user per month in EUR (Basic €1.99, Plus €3.99, Business €5.49) and sold exclusively through certified grommunio partners. Enterprise pricing is custom/quote-based for 1,000+ users or dedicated environments. A free trial is offered alongside the free Community edition for up to 5 users.

CommunityFree

Open source, free of charge, suited for testing, proof-of-concept or small installations.

Up to 5 users. Self-supported via community channels — no manufacturer support.

Basic€1.99/user/mo

Sold exclusively through certified grommunio partners.

From 6 users. Sales & support handled by your grommunio partner.

Plus€3.99/user/mo

Marked as recommended plan; sold through certified partners.

From 6 users. Partner support with grommunio backing.

Business€5.49/user/mo

Sold through certified partners.

From 50 users. Partner support with enhanced response.

EnterpriseQuote

Custom quote-based pricing for large-scale, multi-tenant or dedicated deployments.

From 1,000 users or a dedicated environment. Negotiated SLA, onboarding and roadmap alignment.