Schleswig-Holstein Completes Full Open Source Email Switch

The state of Schleswig-Holstein has successfully migrated its entire public administration email infrastructure from Microsoft Exchange and Outlook to open source platforms. Over the course of six months, more than 40,000 mailboxes—holding in excess of 100 million emails and calendar entries—were transferred to Open-Xchange and Thunderbird, covering roughly 30,000 employees across ministries, judiciary, police and other agencies.

Dirk Schröder, the state’s minister for digital affairs, framed the move as a pivotal step toward “digital sovereignty”, arguing that it reduces dependence on large tech companies and boosts transparency and control over IT infrastructure. Earlier phases of the state’s open source agenda had rolled out LibreOffice as the standard office suite. With the email migration now complete, plans are underway to phase out Microsoft Office entirely and replace Windows with open source operating systems such as Linux. The state also intends to substitute Microsoft SharePoint with Nextcloud for collaboration and adopt open source telephony and video conferencing platforms.

The heimliciNor Schleswig-Holstein is not the first German state to explore open source transitions, but the scale and comprehensiveness of this project have drawn attention. Analyses in tech policy circles now view it as a benchmark for public sector IT reform in Europe. Critics and observers note that although the objectives are ambitious, the process has exposed gaps in planning, stakeholder engagement, and practical resilience.

Police unions have voiced sharp criticism of the implementation. Torsten Jäger, head of the Schleswig-Holstein branch of the German Police Union, described the rollout as “disastrous,” warning that critical information may have been lost and asserting that the transition was rushed. Meanwhile, senior judicial bodies raised alarms about disruptions in court operations and subpoenas when email access lagged or failed altogether. In response, Schröder issued formal apologies to staff in a letter, acknowledging that the scale and complexity of the migration imposed heavy burdens on users.

At a session of the Schleswig-Holstein Landtag, the FDP parliamentary group led calls for stronger oversight and better communication from the digital ministry. Lawmakers cited lengthy periods during which judges reportedly lacked access to their mailboxes and police stations that were effectively cut off from vital digital systems. The FDP proposed a motion demanding a more user-centred approach, insisting that employees be consulted and fully supported—through training, interface optimisation and contingency mechanisms.

Proponents argue the state’s bold approach is now yielding informational returns: having complete control over software stacks enables more agile adaptation to local needs and security strengthening. The government has already committed to sharing its migration tools and experiences with other states and public institutions, positioning Schleswig-Holstein as a de facto standard-setter in open source governance.

Still, technical challenges persist. Users report latency in mailbox syncing, occasional outages, and hurdles in archiving judicial records in compliance with archival law. State officials say a dedicated task force has been assembled to monitor performance, resolve bugs, and stabilise delivery. They emphasise that the first weeks of operation remain a stress test of the system’s robustness.