Exchange 2016 and 2019: What’s Your Plan?

Exchange 2016 and 2019: What’s Your Plan for End of Support?

October 14, 2025. That’s the end of support date for Microsoft Exchange Server 2016 and 2019. What this means is, after that date, there will be no more security updates, bug fixes, or help from Microsoft. If you’re still running either version on-premise, it’s a great time to start planning your exit. Unfortunately, running Exchange in a locked-down environment will not make it safe, and the increased security and compliance risk of unsupported software  increases over time.

What’s the Risk?

Staying on Exchange 2016 or 2019 past the deadline means:

• No security patches, even for critical vulnerabilities
• Compliance issues for frameworks like CMMC, HIPAA, PCI, and others
• Higher maintenance and support burden as environments age
• Availability and operational outages due to a lack of product support if/when needed

What Should You Do?

1. Migrate to Microsoft 365

For most organizations, this is the right move. Exchange Online is more secure, easier to manage, and fully supported. We’ve migrated thousands of mailboxes, including in highly regulated environments. Our white-glove approach means proactive planning, project execution (cutover), and minimal disruption.  We generally do not recommend Exchange Hybrid Mode for most organizations, as it introduces complexity with mail-flow, Autodiscover, certificates, and on-premises Exchange maintenance/co-existence (and sets the stage for a never-ending migration project).  Rather, we use specialized software and project expertise to cleanly stage and migrate Microsoft Exchange (and SharePoint/OneDrive/Teams) data in a one-shot/big-bang approach, usually representing the least amount of risk and the highest level of project success/completion.  No two migrations are ever exactly alike, and each usually has some ‘bumps along the way’, which is normal (if there were an “easy button” for this from Microsoft, we wouldn’t be offering professional services!).  We proactively anticipate and manage through any migration challenges to ensure the project is complete and overall a success.

2. Consider Exchange Server SE

Coming in July 2025, SE is a subscription-based on-prem option. It exists for organizations that truly cannot move to the cloud. That said, we don’t recommend it at this time unless there’s a very specific need. It still requires ongoing patching and maintenance. Also, there’s no in-place upgrade path from Exchange 2016. You’ll need to move to 2019 first. That’s time and effort spent staying on a legacy platform.  There are also special licensing considerations that need to be in place to make the move to Exchange Server SE:

• Qualifying cloud subscription licenses for users (for example, Microsoft 365 E3/E5) If you go this route, all users that access Exchange Server SE must have an E3 or E5 license.
• License (Server and CALs) + SA for Exchange Server 2016/2019 Maintain SA for usage rights and access Exchange Server SE and updates.
• License (Server and CALs) + SA for Exchange Server SE (once released) Maintain SA for Exchange Server SE for usage rights and access to updates.

Hybrid Exchange Setup

Are you just running an Exchange Server in a Hybrid Configuration for some management capabilities, even though all of your mailboxes are already moved to M365?  We could assist with understanding how to remove those dependences as well as assisting with the removal of an Exchange Hybrid Setup.

Ready to Plan?

We specialize in Microsoft 365 / Office 365 and on-premises Exchange migrations, Microsoft license consulting, and helping organizations transition from legacy environments cleanly and confidently.  Let us help you determine what makes the most sense for your environment. We’ll help you stay compliant, reduce risk, and move forward with a plan you can trust.