Download Microsoft Exchange Server 2013 CU 21

Microsoft has already released the 21st Cumulative Update for Exchange Server 2013. Exchange Server 2013 was released in January 2013. Mainstream support from Microsoft will run until April 2018 and extended support will run until April 2023. Only security and time zone updates will be implemented during this extended period. For a general discussion about Exchange Server 2013, you can visit the General Exchange 2013 topic on our Forum. The KB article with number 4099855 mentions the following changes:

Cumulative Update 21 for Exchange Server 2013

Cumulative Update 21 for Microsoft Exchange Server 2013 was released on June 19, 2018. This cumulative update 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 2013.

This update also includes new daylight saving time (DST) updates for Exchange Server 2013. For more information about DST, see Daylight Saving Time Help and Support Center.

Issues that this cumulative update fixes

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

• 4133605 Cmdlets to create or modify a remote shared mailbox in an on-premises Exchange environment
• 4133604 User can’t log on to a POP/IMAP account by using NTLM authentication in Exchange Server 2013
• 4133618 Unexpected error occurs when running the Get-DatabaseAvailabilityGroupNetwork cmdlet in Exchange Server 2013
• 4133620 “HTTP 500 due to ADReferralException” when a user tries to view detail properties of mailboxes in a child domain in Exchange Server
• 4058473 An Office 365 primary mailbox user cannot be assigned full access permissions for an on-premises mailbox in Exchange Server
• 4094167 The MSExchangeRPC service crashes with a System.NullReferenceException exception in Exchange Server 2013
• 4095974 “System.InvalidOperationException” occurs when the “Enable-MailPublicFolder” cmdlet is run against a public folder in Exchange Server
• 4092041 Description of the security update for Microsoft Exchange Server 2013 and 2016: May 8, 2018
• 4294205 POP3 services intermittently stop in an Exchange Server 2013 environment
• 4294204 Changing “IsOutOfService” to “False” in an earlier Exchange Server version does not immediately update in a later Exchange Server environment