Emails outside a UID range are returned when you request for emails by using IMAP

Symptoms

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.

Cause

This issue occurs because the IMAP request isn't correctly handled.

Resolution

To fix this issue, install one of the following cumulative updates:

• Cumulative Update 9 for Exchange Server 2016 or a later cumulative update for Exchange Server 2016

• Cumulative Update 20 for Exchange Server 2013 or a later cumulative update for Exchange Server 2013

Status

Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.

References

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