Assume that you use a client to connect to Exchange Server through Internet Message Access Protocol (IMAP). When you try to request for emails in a UID range of a certain pattern, you may find that the emails that are outside the UID range are returned to the client.
This issue occurs in Microsoft Exchange Server 2016 and Exchange Server 2013.
This issue occurs because the IMAP request isn't correctly handled.
To fix this issue, install one of the following cumulative updates:
Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.
Learn about the terminology that Microsoft uses to describe software updates.