We are excited to announce the general availability of Exchange Server Subscription Edition (SE). This release continues Microsoft’s long tradition of enabling customers to provide enterprise email s...
Updated Aug 06, 2025
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Hello,
We have Exchange 2019 CU15 in our environment with an Active Directory split permission model deployed across two AD sites, each containing four servers. We are planning to install two Exchange SE Servers in each AD site within the same AD forest.
The following are my questions:• Is it necessary to perform Schema and AD preparation with the Active Split permission model using SE setup?
• Are privileged credentials such as Schema, Enterprise, and Domain admin required to introduce SE into the existing Exchange environment?
• Will the existing certificates continue to be valid for Exchange SE?
• Is there any issue if the hardware for the Exchange SE server set differs from the current Exchange 2019 CU15 environment?
• Will the existing Exchange 2019 keys from the year 2022 work for Exchange SE as well?
• Are there any co-existence limitations that we should be aware of?
Thank you for your assistance.
Nino_Bilic
Microsoft
Microsoft- No difference from E2019 CU15. No schema prep is needed unless you are coming from quite old E2019 CU schema.
- Yes. I take it you mean in-place upgrade? No difference - just like any other CU.
- No; hardware requirements stay the same, but assuming that you are talking about new servers, there is nothing new for hardware requirements when creating new Exchange SE servers.
- Yes, in Exchange SE RTM. To keep our promise of Exchange SE RTM = Exchange 2019 CU15, we did not do anything with server keys in SE RTM. This will happen in a later update.
- The only thing you should be aware of is that in ESE CU2, we plan to remove coexistence with E2016/E2019. So by then, make sure that all of those versions are out. Upgrading your organization from current versions to Exchange Server SE | Microsoft Community Hub
Thank you for your responses. Please review the question 3 provided below in detail and respond accordingly.
Question 3: We plan to introduce Exchange SE on new Dell hardware in a different data center, while our current mailbox servers run on HP hardware. There will be 12 servers total: 8 HP servers in one DAG and 4 new Dell servers in another DAG. Mailboxes will eventually move to the Dell servers. Old HP hardware servers would be decomissioned. Will running servers on both HP and Dell hardware during this coexistence period cause any issues?
- Nino_Bilic
No. As long as hardware is appropriately sized for the workload, Exchange is hardware agnostic really. It does not matter if there is a mixture of different manufacturers in the organization.