Microsoft, Exchange ServerProvided updates on 's product roadmap and shared support plans for on-site service users, service providers, and other partners.
- At the end of this year, Exchange Server 2019 It plans to release the final Cumulative Update, also known as CU2024, in 2 H15.
- In the early third quarter of 2025 They will release Exchange Server Subscription Edition (Exchange Server SE).
- They also announced that they will release the first Cumulative Update for Exchange Server SE, CU2025, in late 1.
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Exchange Server 2019 CU15
The CU15 update will bring new features and changes to support the release of Exchange Server SE.
- With Exchange Server 2019 CU15 Transport Layer Security (TLS) 1.3 support will be added, which will phase out the use of old cryptographic algorithms and increase security over previous versions.
- Additionally, certificate management on EAC will be reactivated; new SSL requests can be created on EAC, certificates can be exported as PFX, and PFX import operations can be performed.
Changes in Exchange Server Subscription Edition
- Support for coexistence with Exchange Server 2013 has been removed: Exchange Server 2013 Since it went EOL (End of Life) last year and Exchange Server SE does not support interoperability with unsupported versions, Microsoft has decided to end support for Exchange Server 2013. Users need to uninstall their Exchange 2019 servers before installing Exchange 15 CU2013 or Exchange Server SE RTM or later versions. If Exchange 2013 is detected in the environment, the CU15 and Exchange Server SE installation will stop and display an error message indicating this.
- Support for New Product Keys: Hybrid Exchange Servers will continue to receive free licenses with HCW, and Hybrid licenses obtained with Exchange Server CU15 will continue to be active when Exchange Server SE is released.
- Windows Server 2015 SupportExchange Server 2019 can be installed on Windows Server 2022. CU15 will introduce support for Windows Server 2025, the operating system that will be available to the general public later in the year.
Additional Changes in Exchange Server Subscription Edition
- Updating the Visual C++ redistributable package to the version that ships with Visual Studio 2022
- Removal of UCMA 6.0 support and instant messaging feature on OWA,
- The Windows MSMQ component is no longer loaded during installation,
- Improvements in Exchange Server AMSI integration,
- Added Exchange Server CBC encryption support for PDF files.
Exchange Server Subscription Edition
Exchange Server Subscription Edition (Exchange Server SE) The next version of Microsoft Exchange Server will be available for download via the Microsoft 2025 admin center (formerly known as Microsoft Volume License Service Center) in early Q365 XNUMX. The licensing model for Exchange Server SE is the same as SharePoint Server Subscription Edition, requiring subscription licenses or active oftware assurance for server and user licenses. Free licenses and keys will continue to be provided for Hybrid Server, and will continue to be deployed via the Hybrid Configuration Wizard.
Hardware and operating system requirements for Exchange Server SE, Windows Server 2025 It is the same as Exchange 2019 CU15 with added support.
RTM version of Exchange Server SE, Exchange Server 2019There will be no changes to Active Directory when upgrading from Exchange Server 2019. There will be no Active Directory schema changes beyond what is in Exchange Server 2012, and the Windows Server 2 RXNUMX forest functional level will continue to be supported.
Exchange Server Release Details
The RTM version of Exchange Server SE will reportedly have the same code base as Exchange Server 2019 CU15 to ensure rapid deployment, but with the following changes.
- Only the License agreement, which is an RTF file shown in the GUI version of Setup, will be updated.
- The name will change from Microsoft Exchange Server 2019 to Microsoft Exchange Server Subscription Edition.
- If any Security Updates (SU) are released before CU15, these updates will be included in CU15.
- If any Security Update (SU) is released after CU15, then the RTM version of Exchange Server SE will be code-equivalent to the latest Security Update (SU) in addition to Exchange 2019 CU15.
Upgrading to Exchange Server Subscription Edition (SE)
To further speed up in-place upgrades, in addition to code equivalence, Exchange Server SE will support two types of upgrades: in-place upgrade and legacy upgrade.
In-place upgrade
The quickest and easiest way to migrate from Exchange Server 2019 to Exchange Server SE is to perform an in-place upgrade. The upgrade experience is the same as a Cumulative Update (CU) installation. Once a server is running Exchange Server SE, it will be updated with the CU updates that are rolled out twice a year (in H1 and H2).
Legacy upgrade
Exchange Server SE, It also supports legacy upgrades, which involve creating a new infrastructure and moving namespaces and mailboxes to that new infrastructure. Such operations are used in other scenarios, such as when replacing server hardware or when you want to use a newer version of Windows Server, and these operations will continue to be supported in Exchange Server SE.
If your environment is running Exchange 2016 today and you want to continue running On-Premises Exchange, there is at least one Exchange server upgrade you need to do.
To ensure a timely migration from Exchange Server 2016 to Exchange Server SE, you should perform a legacy upgrade from Exchange 2016 to Exchange 2019 as soon as possible. Once you're running Exchange 2019, you can perform a quick and easy in-place upgrade to Exchange Server SE.
Update Methods for Exchange Server SE from Exchange Server 2019 CU15
As with all previous versions, Exchange Server SE can be used to create a new on-premises Exchange organization and/or can exist in an Exchange organization that contains only supported versions (for example, Exchange 2016 CU23 and/or Exchange 2019 CU14 or later). It cannot be included in an Exchange organization that contains unsupported versions.
| Version in use | Exchange 2019 CU15 | Exchange Server Subscription Edition (SE) |
| Exchange Server 2013 | Not supported in the organization. Upgrade to Exchange 2019 CU14, uninstall Exchange 2013 and update to Exchange 2019 CU15 when available. | Not supported in the organization. Upgrade to Exchange 2019 CU14 or CU15 when possible, uninstall Exchange 2013 and perform an in-place upgrade for Exchange Server SE. |
| Exchange Server 2016 CU23 | Upgrade to Exchange 2019 CU14 and update to CU15 when available. | Upgrade to Exchange 2019 CU14 or CU15 when available, and perform an in-place upgrade of Exchange Server SE. |
| Exchange Server 2016 CU22 and earlier | Not supported in the organization. Upgrade to Exchange 2019 CU14 and update to CU15 when available; or update to Exchange 2016 CU23 now, then upgrade to Exchange 2019 CU15 when available. | Not supported in the organization. Update to Exchange 2016 CU23 and/or upgrade to Exchange 2019 CU14/CU15, then you can do an in-place upgrade for Exchange Server SE when available |
| Exchange Server 2019 CU14 and later | Update CU14 servers to Exchange 2019 CU15 when available. | You can perform an in-place upgrade to Exchange Server SE. |
| Exchange Server 2019 CU13 | Update to Exchange 2019 CU14 and update to CU15 when available. | Not supported in the organization. Update to Exchange Server 2019 CU14/CU15, then perform an in-place upgrade for Exchange Server SE. |
| Exchange Server 2019 CU12 and earlier | Not supported in the organization. Update to Exchange 2019 CU14 and update to CU15 when available. | Not supported in the organization. Update to Exchange Server 2019 CU14/CU15, then perform an in-place upgrade for Exchange Server SE. |
Exchange Server SE CU1
Exchange Server SE will continue to receive Cumulative Updates (CUs) that will be released biannual. Exchange Server SE CU2025 is expected to be released in October 1. Exchange Server SE CU1 will include the following changes:
Kerberos for Server to Server Communication
Kerberos will be used instead of NTLMv2 as the default authentication protocol for communication between Exchange servers. During the CU1 installation, Kerberos (specifically, auth=Negotiate:Kerberos) will be enabled in all virtual directories of the installed server.
Removal of Admin API and RPS
Admin API consisting of REST based APIs will be introduced to enable remote management of Exchange servers. Remote PowerShell (RPS) will be supported in CU1 but will be removed in future CUs.
Uninstall Outlook Anywhere
Exchange Online and Microsoft 365 removed support for Outlook Anywhere (aka RPC over HTTP) a few years ago, and starting with CU1, Outlook Anywhere will be removed from Exchange Server SE. This change may impact any third-party Outlook add-ins that still use this protocol.
Removal of Interoperability Support with Previous Versions
Once CU1 is released, Exchange Server SE will be the only supported version. By then, all previous versions will be unsupported, so installing CU1 will prevent interoperability with any version other than Exchange Server SE RTM or later.
Exchange Server SE Upgrade Recommendation
If you want to run Exchange Server, you need to migrate to Exchange Server 2022 CU2019 on Windows Server 14.
If you are waiting for Windows Server 2025, you can switch to Exchange Server 2019 CU15 as soon as the new operating system is available. If you are using Exchange Server 2019, you should always keep your Exchange servers up to date with a supported CU and the latest Security Update(SU), it is important to apply the latest updates for the Windows operating system and run the Exchange Health Check script regularly.
