Update 6/13/2025: Please see our new blog post for updated timelines of releases as well as additional details on how to get from current versions of Exchange Server to Exchange Server SE: Upgrading ...
Updated Jun 13, 2025
Version 14.0
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And as regards removing the last Exchange Server and using the management tools only, that's not a practical option as it's all Powershell with no EAC. Powershell might well be the best option for bulk actions, but the EAC is the far better option for ad hoc individual changes (e.g. adding an alias to a mailbox). Surely it wouldn't be that difficult for Microsoft to create a product (or installation option for Exchange) which just included the management tools and a lightweight EAC implementation which could only be used for managing hybrid mailboxes?
The current approach is a mess, and despite years of delay and many comments on forums over that time it appears that absolutely nothing is being done to address it.