NHS Wales looks to the future with a major email server upgrade

09 January 2026 

NHS Wales has long relied on Microsoft Exchange servers to support critical email communications, with around seven million emails passing through on-premise systems each month. The Exchange 2016 servers were due to reach end of support in October 2025 and without Microsoft support, any technical issues could threaten the reliability of local and national communications. Recognising this, the NHS Wales M365 Centre of Excellence (M365 CoE) initiated a major project to upgrade the messaging infrastructure.

Planning began in May 2025, with initial testing taking place from June. The M365 CoE began by upgrading a single server, before moving to a phased rollout over the course of four months. The aim was to upgrade six Exchange servers and four Edge servers from Exchange 2016 to Exchange 2019. At the time, the newest version, Exchange Server SE, was not yet released. However, as soon as it became available the team transitioned to this product, positioning NHS Wales at the forefront of secure messaging practices.

The process required meticulous planning to move all mailboxes to the new servers and transfer intricate mail flow settings. One key challenge was the presence of older Exchange 2010 and 2013 servers within some health boards. These legacy servers needed to be decommissioned before the upgrade could continue. The M365 CoE worked closely with health board technical teams to ensure these outdated servers could be retired, demonstrating effective collaboration across NHS Wales.

Despite the tight October 2025 deadline, careful phasing and risk management ensured there was no significant downtime or service disruption. The M365 CoE team’s proactive approach safeguarded the integrity of critical email flows, particularly for departments reliant on legacy applications and timely, sensitive communications.

Now completed, this upgrade has placed NHS Wales in a far more secure and resilient environment. With Microsoft’s move towards minor update releases for Exchange Server SE, the need for disruptive, large-scale upgrades has been eliminated. NHS Wales is well-positioned to pursue further reductions in on-premise infrastructure in the coming months. Plans are already underway to decrease the number of servers, aligning with the broader cloud transition objectives of Digital Health & Care Wales. This project is not only a technical achievement but a strategic milestone on NHS Wales’ journey to modern, efficient, and secure digital communications.