Sovereign alternatives to Microsoft 365 in 2026 – an honest overview

More and more companies and public bodies in Europe are asking whether their email, chat and files have to sit with a US provider. The reason is legal rather than technical: Microsoft, Google and Zoom are US companies, and US law such as the CLOUD Act applies to them even when the data sits in a European data centre. At the same time, nobody wants to give up the AI that has arrived in Microsoft 365 and Google Workspace.

This overview shows the European options as of November 2026 – what they include, where data and AI run, and who each one suits. We make Xenaxio, so we are not neutral; we have tried to describe the others fairly, including where they are the better choice. Features and prices change, so please check the details on the providers’ websites.

Five questions that decide

• Where is the data, and which law applies to the provider? A data centre in Germany is a start; a provider outside US jurisdiction, or your own servers, goes further.
• What does the AI do, and where does it run? Rephrasing text is one thing; an assistant that searches mail, calendar and files and drafts replies is another.
• Can it run on your own servers? For public bodies, professional secrecy and critical infrastructure this often decides.
• Do you need office apps? Word and Excel in the browser are a different category from email, chat and calendar.
• Who operates it? A managed service, a supported product on your servers, or many open-source components your IT runs.

Xenaxio

Email on your domain, calendar, contacts, files, Rooms team chat on Matrix, video meetings and webinars, online booking like Calendly, projects and an AI assistant – in Xenaxio Cloud in Germany or on your own servers, the AI model included. The assistant uses Mistral AI through its EU endpoint or your company’s own model (for example with Ollama or vLLM). It reads what the person may see, saves replies as drafts, creates meetings only after confirmation and records every action in an audit log. An MCP connector brings the workspace into Claude.

Suits teams that want AI in their daily communication with clear limits, and organisations that want to start in a managed cloud and move to their own servers later. Not a fit if you need office apps from the same provider, recordings of meetings or end-to-end encryption of all mail.

Xenaxio in detail · On your own servers

IONOS Nextcloud Workspace

IONOS and Nextcloud launched a managed workspace in German data centres in November 2025: Nextcloud files, calendar, contacts, Talk for chat and video, an office suite and an AI assistant on IONOS’s own AI platform, at a low price per person with a lot of storage. It is a managed service; IONOS does not offer it for your own servers.

Suits teams that want a well-known German hosting brand, much storage and office in the browser. Xenaxio vs IONOS Nextcloud Workspace

openDesk

openDesk is the open-source workplace promoted by the German federal government’s ZenDiS: Open-Xchange for mail and calendar, Nextcloud, Element on Matrix, Jitsi, Collabora, OpenProject and XWiki under one portal. There is a free Community Edition to run yourself and an Enterprise Edition through service providers; in October 2026 a company was founded to sell it to the private sector. An AI assistant was shown as a prototype in October 2026.

Suits public bodies that want the federal reference stack and organisations that need every component to be open source – and have the IT staff to run it. Xenaxio vs openDesk

Nextcloud, self-hosted

Nextcloud is open source and runs on your own servers: files, calendar, mail, Talk and an assistant that can use local language models. You need someone to look after servers, updates, security and backups.

Suits organisations with their own IT that want to run everything themselves.

Zoho Workplace

Zoho bundles mail, Cliq chat, WorkDrive, meetings and office apps at very low prices, with its own AI Zia and data centres in the EU. Zoho is based in India, and Workplace runs only in Zoho’s cloud.

Suits teams for whom price and breadth – office, CRM and many business apps from one vendor – matter most. Xenaxio vs Zoho Workplace

Proton

Proton from Switzerland encrypts mail, calendar and drive end to end and, since 2026, video calls with Proton Meet; its business plans include a password manager and VPN. Its assistant Lumo runs on open models on servers Proton controls, as a separate chat – what Proton cannot read, no AI on the server can search.

Suits teams for whom end-to-end encryption of every email is a must. Xenaxio vs Proton

Tuta, mailbox.org and other German mail providers

Tuta (Hanover) encrypts end to end with its own apps; mailbox.org (Berlin) offers mail, calendar and office in the browser. They are strong, established mail services – with little AI in the mailbox.

Suits teams that mainly need secure email from Germany.

A quick guide

• AI in daily work, with the option of your own servers: Xenaxio.
• Managed German cloud with office in the browser and lots of storage: IONOS Nextcloud Workspace.
• Public body, everything open source, own IT team: openDesk or self-hosted Nextcloud.
• Lowest price and many business apps: Zoho Workplace.
• End-to-end encryption above all: Proton or Tuta.

Whichever you choose: check where the AI runs, not only where the mail is stored – and whether you can leave again with your data. Xenaxio uses open standards (IMAP, SMTP, CalDAV, CardDAV, Matrix) and an open-source web client for exactly that reason.

More comparisons

We compare Xenaxio with Microsoft 365, Google Workspace, Microsoft Teams, Slack, Zoom and Calendly on their own pages; all of them are in the overview. You can try Xenaxio in the live demo without signing up, or request access.