This cumulative update includes fixes for nonsecurity issues and all previously released fixes for security and nonsecurity issues.

Known issues in this cumulative update

• 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 execute the /PrepareAD command during the first server installation. Installation will finish only if the user who initiated SETUP has the appropriate permissions.
• The Set-SendConnector cmdlet does not work for Exchange Server 2016 in hybrid scenarios that have a Edge server installed. For more information, see KB 4523519.

Issues that this cumulative update fixes

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

• 4502154 Providing information to administrators when auto forward limit is reached in Exchange Server 2016
• 4502155 “The primary SMTP address must be specified when referencing a mailbox” error when using impersonation in Exchange Server 2016
• 4502156 Audit logs aren’t updated when “-WhatIf” is used as $false in the command in Exchange Server 2016
• 4502157 The Find command not returning the HasAttachments element in Exchange Server 2016
• 4502158 SyncFolderItems contains duplicated ReadFlagChange items in Exchange Server 2016
• 4502131 “TLS negotiation failed with error UnknownCredentials” error after updating TLSCertificateName on Office 365 send connector in Exchange Server 2016 hybrid environment
• 4502132 Can’t reply to old emails after migration even though old legacyExchangeDN is set to migrated mailbox in Exchange Server 2016
• 4502136 The response of FETCH (BODYSTRUCTURE) command of IMAP violates RFC 3501 in Exchange Server 2016
• 4502140 Can’t preview an eDiscovery search when there are multiple domains in Exchange Server 2016
• 4502141 Appointment that’s created by responding to an email message doesn’t show in any of Outlook calendar views in Exchange Server 2016
• 4502133 Can’t use Outlook on the web to reply a partner email through mutual TLS in Exchange Server 2016
• 4488396 Can’t search any results in manually added shared mailbox in Outlook in Exchange Server 2016
• 4488078 Public folder contact lists don’t show contact’s profile picture in Outlook on the web in Exchange Server 2016
• 4499503 Heavy organizational forms traffic due to materialized restriction when organization forms library has more than 500 items in Exchange Server 2016
• 4503027 Description of the security update for Microsoft Exchange Server 2019 and 2016: June 11, 2019