In a Microsoft Exchange Server environment, consider the following scenario:
A user is hidden from the global address list (GAL).
The user has an Address Book Policy applied.
In this scenario, the From field on items in the Sent Items folder on an ActiveSync device shows the LegacyDN of the user instead of the display name or SMTP address.
The issue occurs because the LDAP search for the user is not resolved to their display name or SMTP address.
Cumulative update information
For Exchange Server 2013
To resolve this issue, install Cumulative Update 15 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.