Consider the following scenario:
You have the Send As permission on a mail distribution group in a Microsoft Exchange Server 2013 environment that has Cumulative Update 6 installed.
You send an email message to a mail enabled public folder from the distribution group.
In this scenario, the email message is not delivered to the public folder, and no non-delivery report (NDR) is returned. Additionally, the message tracking log shows that the user is not authorized.
This issue occurs because a mail distribution group cannot create items in a mail enabled public folder, unless you change it to a security group.
To resolve this issue, install Cumulative Update 7 for Exchange Server 2013.
Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.