Symptoms
When a user accepts or declines a forwarded meeting invitation in a Microsoft Exchange Server 2013 environment, the accept or decline message is sent to the forwarder instead of to the meeting organizer.
For example, user A sets a rule to forward all messages to user B. When the organizer sends a meeting invitation to both user A and user B, user B receives two invitations. Regardless of which invitation user B accepts or declines, the response is sent to user A instead of to the meeting organizer.Cause
This issue occurs because the Inbox forwarding rule can't preserve the original organizer in Exchange Server 2013.
Resolution
To fix this issue, install Cumulative Update 13 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.