EU Sovereignty Score
Self-hosted / open sourceBusiness Email & GroupwareHeadquarters: AT

grommunio: sovereignty score and 8 European alternatives

grommunio is an open-source collaboration platform positioned as a replacement for Microsoft Exchange. It combines email, calendar, chat, files and video meetings. Outlook for Windows connects natively over MAPI/HTTP, and EWS, Exchange ActiveSync, IMAP/POP3/SMTP and CalDAV/CardDAV are also supported. The platform further includes S/MIME, single sign-on through SAML and OIDC, multi-tenancy and built-in antispam and malware protection. A free Community edition exists; paid subscriptions add manufacturer support.

grommunio GmbH is based in Vienna, Austria. The source code is published on GitHub and Codeberg under an OSI-approved licence. You can host the platform yourself, on premises or in a private cloud, or obtain it through a certified European partner. Ready-to-run images are available as ISO, OVA or container. Because the software runs on Linux without Windows Server licences and can be self-hosted, European organisations decide for themselves where their email and calendars are stored.

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Sovereignty score
94 / 1000 = high exposure
100 = sovereign
  • Jurisdiction SOV-2100
    Headquartered in the EU: European law applies
  • Data residency SOV-3100
    EU-only hosting
  • Cryptographic key sovereignty SOV-390
    Self-hostable: encryption keys under your own control
  • Freedom from lock-in SOV-680
    Open source: low switching costs
  • Source & runtime sovereignty SOV-4 · SOV-6100
    Source code auditable, forkable and self-hostable

SOV codes: the matching objective in the European Commission's Cloud Sovereignty Framework. Official source

How the score is calculated

Facts and evidence

Last checked October 4, 2026
Headquarters
AT (EU)Verified by hand
Sovereignty model
Open-source, distributedVerified by hand
Data hosting
EUVerified by hand
Open-source
YesVerified by hand
GDPR-compliant
YesVendor-stated
Hosting signal
CLOUDFLARENET - Cloudflare, Inc., US (US)Technically measured
Category
Business Email & Groupware
Type
Product
Website
grommunio.com ↗

The hosting signal shows the network that serves the vendor's website, often a CDN, and not necessarily where the service or your data is hosted. How we verify · Something wrong? Suggest a correction

Top EU-based & GDPR-compliant alternatives to grommunio

The European alternatives to grommunio come from our knowledge base of over 6,800 vendors. We only list vendors headquartered in the EU or the EEA; fully European-owned vendors rank before vendors with a foreign owner. For each alternative you see the country, the open-source status and a short description.

Score per alternative: 0 = high exposure, 100 = sovereign

28 European Business Email & Groupware vendors are in the catalogue. View the whole category · Submit an alternative · View category on the map

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Why digital sovereignty matters with grommunio

grommunio is headquartered in AT and therefore falls under European law: the GDPR, NIS2 and the Data Act. No foreign legislation can compel access to your data.

Data is hosted exclusively in the EU, so grommunio scores best on data residency.

grommunio is open source. You can audit the source code, self-host the software and keep the encryption keys under your own control. Switching is easier because data and software are not tied to a single party.

What this means for your organisation depends on your whole stack and context. The free assessment weighs grommunio together with your other vendors and gives a total score, a heatmap and the main risk drivers.

Frequently asked questions

What is the best European alternative to grommunio?

It depends on your use case. Strong EU alternatives to grommunio include Axigen, Benno MailArchiv and BlueMind. On this page you can compare 8 EU alternatives by jurisdiction, data residency and open-source status.

Are there open-source alternatives to grommunio?

Yes. Open-source EU alternatives to grommunio include Benno MailArchiv, CipherMail, Dovecot and EGroupware. These keep your data fully under your own control and let you self-host if you want to.

Is grommunio GDPR-compliant and where is the data hosted?

grommunio is headquartered in AT (EU) and hosts data in EU. It is also open-source, so you can self-host it. That makes grommunio an EU-sovereign choice in its own right; the EU alternatives on this page are comparable European tools.

Details and sources

Verified by handHeadquarters, owner, hosting locations and licence have been checked by us against public sources. Free of charge and for every vendor, not a paid label. Nothing in this knowledge base is taken over automatically. Last checked on October 4, 2026.

Sources

Public sources used in the latest check of this record.

Compliance evidence

The links below point to the vendor's own public documents. We only record what we found: a missing link means "not found publicly", not "not compliant".

No public compliance evidence has been recorded for this vendor yet. Do you know its DPA or subprocessor list? Something wrong? Suggest a correction

Digital sovereignty in Business Email & Groupware

Business Email & Groupware: Business email servers, groupware, calendar and contact management. In this category the choice of vendor determines who has legal access to your data, where that data lives and how easily you can switch later.

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8 European alternatives to grommunio — GDPR-compliant & EU-hosted · EU Sovereignty Score