# grommunio

> grommunio is the native, open-source alternative to Microsoft Exchange & Microsoft 365 - secure email, calendar, contacts, chat, video and files on one sovereign, European platform. Keep Outlook and every existing client; self-host on infrastructure you control.

grommunio implements the native Exchange protocols (MAPI/HTTP, EWS, Exchange ActiveSync) alongside open standards (IMAP4, POP3, SMTP, CalDAV, CardDAV, LDAP), so existing clients connect without plugins or connectors. The platform is built on the lightweight C/C++ gromox core. Developed by grommunio GmbH (Vienna, Austria) and sold through certified partners. The site is available in 15 languages; canonical English URLs are listed below.

## Product
- [What is grommunio](https://grommunio.com/what-is-grommunio/): Platform overview and architecture.
- [Features](https://grommunio.com/features/): Mail, calendar, contacts, chat, video, files and administration.
- [Technology](https://grommunio.com/technology/): The gromox core, supported protocols and deployment options (appliance, software packages, containers).
- [Security](https://grommunio.com/security/): Security model, S/MIME, layered hardening and coordinated vulnerability disclosure.
- [Pricing](https://grommunio.com/pricing/): Subscription tiers and what each includes.
- [Exchange alternative & cost comparison](https://grommunio.com/exchange-alternative/): Total cost of ownership versus Microsoft, Google, Kerio and Zimbra.
- [Live demo](https://grommunio.com/demo/): Try grommunio in the browser.

## Downloads
- [Appliance](https://grommunio.com/download/): Ready-to-run virtual appliance.
- [Manual install](https://grommunio.com/download-for-manual-install/): Packages for major Linux distributions.
- [Mobile apps](https://grommunio.com/download-mobile-apps/)
- [Desktop apps](https://grommunio.com/download-desktop-apps/)
- [Outlook add-ins](https://grommunio.com/download-outlook-add-ins/)

## Partners & support
- [Become a partner](https://grommunio.com/become-a-partner/)
- [Find a partner](https://grommunio.com/find-a-partner/)
- [Support](https://grommunio.com/support/)

## Resources
- [Blog & news](https://grommunio.com/blog/)
- [Release notes](https://grommunio.com/release-notes/)
- [Documentation](https://docs.grommunio.com/)
- [Community](https://community.grommunio.com/)
- [GitHub](https://github.com/grommunio)
- [Codeberg](https://codeberg.org/grommunio)

## Company
- [Company](https://grommunio.com/company/)
- [Contact](https://grommunio.com/contact/)
- [Jobs](https://grommunio.com/jobs/)
- [Press articles](https://grommunio.com/press-articles/)
- [Press](https://grommunio.com/press/)

## Optional
- [Sitemap](https://grommunio.com/sitemap-index.xml)
- [Security contact](https://grommunio.com/.well-known/security.txt)