Assume that one user's display name is the same as another user's alias. When you search for a user in the Exchange Control Panel (ECP), a different user is returned instead of the intended user. This causes an incorrect Forwarding Rule to route email to an unintended user after you create an Inbox rule.
This issue occurs because the Recipient property is constructed incorrectly when you query by using Lightweight Directory Access Protocol (LDAP).
Exchange Server 2016
To resolve this issue, install Cumulative Update 9 for Exchange Server 2016 or a later cumulative update for Exchange Server 2016.
Exchange Server 2013
To resolve this issue, install Cumulative Update 20 for Exchange Server 2013 or a later cumulative update for Exchange Server 2013.
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.