The authorities of the German federal state removed Microsoft Exchange Server and Outlook and switched to open source software

In mid-October 2025, it became known that the authorities of the federal state of Schleswig-Holstein, located in northern Germany, completed one of the stages of a large-scale project to abandon the use of Microsoft software products. Instead of software from the Redmond corporation, open source solutions are being implemented.

As noted by The Register, as part of the software replacement, the Microsoft Exchange Server platform for messaging and collaboration gave way to the Open-Xchange server. However, the Microsoft Outlook email client has been replaced with Mozilla Thunderbird. The migration process covered more than 40 thousand accounts and over 100 million emails and calendar entries.

In November 2021, it was reported that the authorities of Schleswig-Holstein are seeking to abandon proprietary products, including Microsoft Office, in favor of open source software. Then it was said about the deployment of the LibreOffice office suite. There is also a transition from Microsoft SharePoint (a collaboration and content management platform) to Nextcloud. In addition, Linux distributions are evaluated for use on personal computers instead of Windows.

Authorities in Schleswig-Holstein also note that while LibreOffice office applications are seen as a local alternative to Microsoft products, much of the work is expected to be done through a browser in the long term. We are talking about the use of various cloud services, which users can access from any device and from anywhere with an Internet connection.

The Register adds that initiatives to abandon Microsoft products are being implemented in other regions of Germany. So, Munich switched to Linux in 2013, but about four years later began a project to return to Windows.^[1]

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