Auto-responses and Out of office replies to Campaigns do not log to Entity record Messages tab

When response is sent to Return-Path email address (autoresponder responded), below happens:

1. Campaign statistic is not updated (not logged as Responded). 
2. Auto-response is not attached to Customer record.
3. Auto-response is not attached to Employee record (Employee who sent the Campaign).

Current NetSuite functionality: Auto responses are not attached either to Campaign nor to Employee, Contact or Customer records.

The concern is logged under Enhancement #175857.