As the end of support looms for Exchange Server 2016 and approaches for Exchange Server 2019, IT departments worldwide face a critical juncture. Continuing to operate these versions beyond their lifecycle dates introduces significant and unacceptable security risks that every organization must address proactively. Ignoring these deadlines can leave your infrastructure vulnerable to emerging threats, data breaches, and compliance issues.
The End of Support for software means Microsoft will no longer provide vital security updates, bug fixes, or technical assistance. For a platform as central to communication and data as Exchange Server, this cessation of support is particularly dangerous. Without regular security patches, known vulnerabilities can be exploited by malicious actors, potentially leading to unauthorized access, data theft, service disruption, and reputational damage. The lack of support also means troubleshooting critical issues becomes much harder, impacting operational efficiency and reliability.
For organizations still running Exchange 2016 or Exchange 2019, now is the absolute critical time to act. Delaying a plan for moving away from these unsupported platforms is essentially inviting security risks into your environment. The primary recommended path forward for most businesses is migration.
There are typically two main options for migrating:
- Migrate to Exchange Online (Microsoft 365): This is the most common and often recommended path. Moving to the cloud offers continuous updates, enhanced security features, scalability, and reduced on-premises management overhead. Exchange Online is a modern, secure, and fully supported service.
- Migrate to a newer, supported version of Exchange Server on-premises: If cloud migration isn’t immediately feasible due to specific requirements or regulations, upgrading to the latest supported version of Exchange Server on-premises is an alternative. However, this still requires infrastructure management and planning for future upgrades.
Regardless of the chosen destination, the migration process requires careful planning and execution. Key steps include assessing your current environment, planning the migration strategy (e.g., cutover, staged, hybrid), preparing the target environment, migrating mailboxes and data, and finally, decommissioning the old servers.
Security must be at the forefront of this transition. Ensure your migration process is secure, and once migrated, leverage the enhanced security features of the new platform, whether that’s the robust protections in Exchange Online or the updated capabilities in a newer on-premises version.
Failing to migrate off unsupported Exchange Servers is not merely a technical oversight; it is a significant security vulnerability that could have severe consequences. IT leaders must prioritize this task, secure the necessary resources, and execute a timely migration plan to safeguard their organization’s communications and data infrastructure against present and future threats. The time to act is now to avoid falling victim to easily preventable security breaches stemming from unsupported software. Protecting your organization starts with ensuring your core infrastructure, like email, is on a supported and secure platform.
Source: https://www.helpnetsecurity.com/2025/05/30/exchange-server-2016-2019-end-of-support/
