In addition to the obvious new features, Microsoft has introduced some background improvements in Exchange Server 2019. These are primarily security and performance enhancements. For more protection against attackers, Microsoft primarily provides the above-mentioned option of using Exchange in combination with Windows Server Core. At the same time, however, the new version relies on stricter rules: With the move to Exchange 2019, only the TLS protocol from version 1.2 will still be supported. All earlier versions are no longer secure and are therefore no longer supported by Exchange - Microsoft is forcing administrators to be more secure.
In addition, the new Exchange version provides administrators with more ways to limit access to the configuration area (Admin Center & Powershell) of the servers with the Client Access Rules. This also provides more security: For example, admins can now only allow certain IP addresses and can therefore block access from outside directly using the server without having the rely on an additional firewall.
Even more has happened with the performance of the new Exchange Server. The major innovations in the form of MCDB, DDC and the change in the search index have also been highlighted above. However, Exchange Server 2019 contains even more improvements: By switching from Workstation Garbage Collection (GC) to Server GC, available performance can be better integrated. Server GC handles more requests per second than the workstation version. However, this only brings a boost in efficiency if multiple processor cores are used. This is why up to 48 processor cores can be used in parallel in Exchange 2019.
Since the changes in Exchange 2019 also focus on improving memory, Microsoft has provided better support for modern hardware in this context. In addition to the usual HDDs, you can now also use SSD memory in your Exchange Server – together with the traditional hard disks. A total of 256 GB of RAM is now available.