Exchange Server On-Prem? Get Ready for CU15 and the Future of Exchange SE
If you’re still running an on-premises Exchange Server, there’s some important news for you: Exchange Server 2019 CU15 is still in development, and Microsoft is making sure it’s as close to code equivalent as possible to the upcoming Exchange Server Subscription Edition (SE).
Microsoft’s Exchange Team recently shared an update on the progress of CU15, highlighting key improvements and feature updates that will ensure a smoother transition to Exchange SE when it becomes available. If you’re relying on Exchange 2019, it’s critical to stay on the latest version so you can apply CU15 as soon as it’s released.

What’s Coming in CU15
While details are still emerging, CU15 is shaping up to be more than just another cumulative update. Here’s why it matters:
- Code Parity with Exchange SE – Microsoft is working to align CU15’s codebase with Exchange SE, making future upgrades more seamless.
- Feature Updates – Expect enhancements that improve stability, security, and potentially new functionality to bridge the gap between on-prem and cloud-based Exchange solutions.
- Security & Compliance Readiness – Keeping up with Exchange updates ensures that your email infrastructure remains secure and compliant with the latest security standards.
Why You Should Be on the Latest Exchange 2019 Version
If you’re still running an older version of Exchange, now is the time to upgrade to the latest CU. Microsoft has made it clear that being on an up-to-date Exchange 2019 environment will make the transition to CU15 and eventually to Exchange SE much easier.
Waiting too long to update could leave you in a difficult spot—especially if older CU versions don’t support a direct path to Exchange SE when it launches.
What Should You Do Now?
- Check Your Current Exchange Version – Ensure you’re on the latest CU of Exchange 2019 to prepare for CU15.
- Plan for CU15 Deployment – Once CU15 is released, apply it as soon as possible to benefit from its improvements.
- Stay Engaged with Microsoft Updates – Keep an eye on Exchange Team blogs and announcements for new details on CU15 and Exchange SE.
Final Thoughts
Microsoft is actively developing the future of Exchange Server, and CU15 is a critical step in that journey. If you’re running Exchange on-prem, staying up to date ensures better security, improved performance, and an easier transition to the next generation of Exchange.
For the latest details, check out Microsoft’s official blog on the topic:
When is Exchange 2019 CU15 Coming?
Are you prepared for the next Exchange update? We’re here to help with your migration strategy!

Chris Hinch
Microsoft Practice Director
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