Introduction to Exchange 2019 CU15
Microsoft Exchange Server 2019 CU15 is coming out next year and it brings new features but also one that was taken away a few CU’s ago, the ability to request a new certificate from the EAC.
Along with support from Transport Layer Security (1.3), the coexistence section is where many are going to fall short because they have not upgraded to Exchange 2016 or Exchange 2019 and are still running Exchange 2013.
Understanding the System Requirements
Exchange 2019 CU15 will prepare the way for Exchange Server SE, however you cannot just deploy Exchange Server SE.
You need to remove any legacy servers in the environment. If you are running an Exchange 2013 server purely for keeping that legacy application working because it does not work with anything else or you are still using Exchange 2010 and want to move the Exchange Server SE, you cannot introduce Exchange Server SE until those servers have been removed.
There are many organizations running Exchange 2010 and there is no direct upgrade path to Exchange 2019 so you would need to do multiple hops to get to a supported version before even considering the new Exchange Version.
If you are running old versions of Outlook, you will need to upgrade to a newer version. Also weigh up the costs between buying licenses or moving to M365 that provides a license and software.
Preparing Your Current Environment
Here are a few high level steps that you would need to look at prior to deploying Exchange Server SE:
- Upgrade Exchange 2019 to CU14 and the latest Security update
- Remove Exchange 2013 or Exchange 2016 servers
- If you are running Exchange 2013, implement new Exchange 2019 servers and start your migration and then retire the Exchange 2013 servers.
- If you are running legacy versions of Outlook, ensure to cater for upgrading to a supported version for Exchange 2019 and Exchange Server SE.
- Upgrade any Hybrid Servers.
This task gives you the opportunity to perform a clean up as well. This can include the following:
- Remove old accounts/mailboxes that are no longer required
- Remove or clean up distribution groups
- If you had X number of servers that catered for X number of users and those numbers have reduced, consider scaling down. This will save on Hardware costs, Licensing costs for Windows, Exchange and CAL’s for users.
What is new in Exchange Server SE and Exchange 2019 CU15
As mentioned above, Exchange 2013 co-existence is not supported with Exchange Server SE
You will be able to install Exchange 2019 CU15 on Windows Server 2025
You will need new product keys as outlined by the Exchange Team.
Exchange Server SE CU1 will have the following key changes, you need to prepare for this as it does affect a number of items, including the fact that Outlook Anywhere will be removed which many are still using. Below is a snippet from the Exchange team blog:
- Kerberos for server-to-server communication
- Adding support for an Admin API and deprecating RPS
- Removing Outlook Anywhere
- Removal of support for co-existence with earlier versions
- Updating the Visual C++ redistributable to the version that ships with Visual Studio 2022
- Removal of support for UCMA 4.0 and the instant messaging feature in Outlook on the web
Upgrade paths
I am very excited that we will be able to do in-place upgrades on Exchange 2019. Something that I have always wanted.
You can do this from Exchange Server 2019 only that is on a supported CU.
Any other upgrades will require new hardware, like we have done previously.
Conclusion and Future Outlook
With many changes coming, be sure to prepare your environment and fast track your upgrade process. You can read all about the changes coming in 2025 and see where you need to chat to your CIO/IT Manager on the way forward:
https://techcommunity.microsoft.com/blog/exchange/exchange-server-roadmap-update/4132742