Cumulative Update 6 for Exchange Server 2019

Cumulative Update 6 for Microsoft Exchange Server 2019 was released on June 16, 2020. This cumulative update is a security update. It includes fixes for nonsecurity issues and all previously released fixes for security and nonsecurity issues. These fixes will also be included in later cumulative updates for Exchange Server 2019. 

This update also includes new daylight saving time (DST) updates for Exchange Server 2019. For more information about DST, see Daylight Saving Time Help and Support Center.

• In multidomain Active Directory forests in which Exchange is installed or has been prepared previously by using the /PrepareDomain option in Setup, this action must be completed after the /PrepareAD command for this cumulative update has been completed and the changes are replicated to all domains. Setup will try to run the /PrepareAD command during the first server installation. Installation will finish only if the user who initiated Setup has the appropriate permissions.
  
  Notes
  • If you are upgrading from Cumulative Update 2 for Exchange Server 2019 or a later cumulative update for Exchange Server 2019 to Cumulative Update 6 for Exchange Server 2019, there’s no need to run the /PrepareAD or /PrepareDomain. No additional actions (prepareAD, prepareDomain, or assigning permissions) are required.
  • If you have ever skipped a Cumulative Update (for example, you are upgrading from an earlier version before Cumulative Update 2 for Exchange Server 2019), or this is a first Exchange Server installation in the AD, then this Known Issue section should be taken care of.
    • About the /PrepareDomain operation in multidomain:
      
      The /PrepareDomain operation automatically runs in the Active Directory domain in which the /PrepareAD command is run. However, it may be unable to update other domains in the forest. Therefore, a domain administrator should run the /PrepareDomain in other domains in the forest.
    • About the permission question:
      
      As the /PrepareAD is triggered in Setup, if the user who initiates Setup isn't a member of Schema Admins and Enterprise Admins, the readiness check will fail and you receive the following error messages.
      
      
      
      To avoid the errors, either the user should join Schema Admins and Enterprise Admins groups or another user in Schema Admins and Enterprise Admins groups manually runs the /PrepareAD for this Cumulative Update first. Then, the Exchange admin user can start Setup.
  • Autodiscover Event ID 1 occurs after you install Cumulative Update 3 for Exchange Server 2019. For more information, see KB 4532190.
  • After updating to this cumulative update, in some cases you might see the string "&nbsp" in the body of an item that has been moved between folders or mailboxes using Outlook in Online Mode.

This cumulative update also fixes the issues that are described in the following Microsoft Knowledge Base articles:

• 4559441 Foreign language characters set in RejectMessageReasonText of a transport rule aren't shown correctly in Exchange Server 2019
• 4547707 Enable piping for Restore-RecoverableItems in Exchange Server 2019
• 4549689 HMA EvoSTS certificate rollover causes authentication prompts due to stalled key on worker process spawn (warmup phase) in Exchange Server 2019
• 4559446 Changes to Outlook on the web blocked file extensions and MIME types in Exchange Server 2019
• 4559440 Export to a PST for an eDiscovery search fails Exchange Server 2019
• 4559439 EAS creates failure report if a message with unknown recipients is in Drafts in Exchange Server 2019
• 4559442 2080 Events caused by empty values in HKLM\SYSTEM\CurrentControlSet\Services\MSExchange ADAccess\Instance0 in Exchange Server 2019
• 4559438 Edge Transport server hangs in Exchange Server 2019
• 4559443 Managed Folder Assistant fails with Event ID 9004 NotInBagPropertyErrorException in Exchange Server 2019
• 4559437 PR_RECIPIENT_ENTRYID is computed if no email address or type in Exchange Server 2019
• 4559444 Conversion from HTML to RTF removes non-breaking space in Exchange Server 2019
• 4559436 Attachments with properties (like Azure Information Protection labels) not always matching in Exchange Server 2019
• 4559435 Introduce an OrganizationConfig flag to enable or disable recipient read session in Exchange Server 2019

Volume Licensing Center

To get Cumulative Update 6 for Exchange Server 2019, go to Microsoft Volume Licensing Center.

Note The Cumulative Update 6 package can be used to run a new installation of Exchange Server 2019 or to upgrade an existing Exchange Server 2019 installation to Cumulative Update 6.

Prerequisites

This cumulative update requires Microsoft .NET Framework 4.8.

A component that's used within Exchange Server requires a new Visual C++ component to be installed together with Exchange Server. This prerequisite can be downloaded at Visual C++ Redistributable Package for Visual Studio 2012.

For more information about the prerequisites to set up Exchange Server 2019, see Exchange 2019 prerequisites.

Restart requirement

You may have to restart the computer after you apply this cumulative update package.

Registry information

You don't have to make any changes to the registry after you apply this cumulative update package.

Removal information

After you install this cumulative update package, you can't uninstall the package to revert to an earlier version of Exchange Server 2019. If you uninstall this cumulative update package, Exchange Server 2019 is removed from the server.

File hash information

For more information about the deployment of Exchange Server 2019, see Release notes for Exchange 2019.

For more information about the coexistence of Exchange Server 2019 and earlier versions of Exchange Server in the same environment, see Exchange 2019 system requirements.

For more information about other Exchange updates, see Exchange Server Updates: Build numbers and release dates.

Learn about the terminology that Microsoft uses to describe software updates.