Exchange 2019 CU10 and Exchange 2016 CU21

Cumulative Update 10 for Exchange 2019 is now available as well as Cumulative Update 21 for Exchange 2016. This is the last planned CU for Exchange 2016.

They both contain the same 8 documented new fixes or improvements, as well as all previously released fixes and security updates for their respective Exchange version and the latest DST updates. Each CU also contains 1 unique fix that does not apply to the other.

The biggest change is that these CU include Exchange Server integration with AMSI (Antimalware Scan Interface) which provides real-time scanning and blocking of malicious HTTP requests.

Other notable improvements, changes and fixes are;

  • KB5004612 Message body not displayed in OWA if the message was added in Outlook to a new mailbox.
  • KB5004615 “InvalidOperationException” and Store Worker process crashes during mailbox move.
  • KB5004616 Changing the email address in EAC doesn’t work in modern browsers.
  • KB5004622 “Cannot Send Mail – Your mailbox is full” error when you use iPhone mail to send very large attachments.

This release includes new updates to the Active Directory Schema for Exchange 2019 and Exchange 2016.
The next planned quarterly update for Exchange 2019 is in September 2021.

Exchange 2019: CU10 KB5003612Download
Exchange 2016: CU21 KB5003611DownloadUM Language Pack
View: Blog post of the Exchange Team about CU10 for Exchange Server 2019 and CU 21 for Exchange 2016.