This CU provides the following fixes and improvements (

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

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