What’s new when upgrading from Exchange 2016 to Exchange 2019?
Windows Server Core support: Running Exchange on a Windows deployment with less surface area means less attack surface area and fewer components to service.
Block external access to Exchange admin center (EAC) and the Exchange Management Shell: You can use Client Access Rules to only allow administration of Exchange from the internal network instead of using complex network and firewall rules.
TLS 1.2 is the only version that’s enabled by default: Exchange Server 2019 includes important changes to improve the security of client and server connections. The default configuration for encryption will enable TLS 1.2 only and disable support for older algorithms (namely, DES, 3DES, RC2, RC4 and MD5). It will also configure elliptic curve key exchange algorithms with priority over non-elliptic curve algorithms. In Exchange Server 2016 and later, all cryptography settings are inherited from the configuration specified in the operating system. For additional information, see Exchange Server TLS Guidance.
Improved search infrastructure: The completely rebuilt search infrastructure for cloud scale and reliability in Exchange Online is now available in Exchange 2019. This new search infrastructure allows for indexing of bigger files, simpler management, and better search performance.
Faster, more reliable failovers: The changes to the search architecture result in significantly faster and more reliable failover over between servers.
Metacache database: Improvements at the core of Exchange’s database engine enable better overall performance and take advantage of the latest storage hardware, including larger disks and SSDs.
Modern hardware support: Exchange now supports up to 256 GB of memory and 48 CPU cores.
Dynamic database cache: The information store process employs dynamic memory cache allocation optimizing memory usage to active database usage.
Calendar – Do Not Forward: This is similar to Information Rights Management (IRM) for calendar items without the IRM deployment requirements. Attendees can’t forward the invitation to other people, and only the organizer can invite additional attendees.
Calendar – Better Out of Office: Additional options when you won’t be in the office. Key options include: add an event to your calendar that shows you as Away/Out of Office, and a quick option to cancel/decline meetings that will happen while you’re away.
Calendar – Remove-CalendarEvents cmdlet: Enables administrators to cancel meetings that were organized by a user that has left the company. Previously, conference rooms or meeting attendees would have these defunct meetings permanently on their calendars.
Email address internationalization (EAI): Email addresses that contain non-English characters can now be routed and delivered natively.