When a Microsoft Exchange Server 2013 mailbox user tries to forward a meeting request that is from an external sender, Outlook Web App displays the following error message, and the user cannot forward the meeting request:
Error: You don't have the permissions required to send messages from this mailbox.
If the user sends the meeting request by using Microsoft Outlook, the user receives a non-delivery report (NDR) that contains the following information:
This issue occurs because the SendAs
check encounters an exception.
To resolve this issue, install the following cumulative update:
Description of Cumulative Update 3 for Exchange Server 2013
Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.