How can I prevent Exchange 2003 from sending Delivery Status Notifications ?
The problem we have is that our server has been marked as "low reputation" by the Barracuda Spam Filter because we reply to every email with a non existing receiver address. The server then send a Delivery Status Notification. We really need get back our reputation, so I am searching for a way to disable this behaviour.
On a stock Exchange 2003 install, open the "Global Settings" container, highlight "Internet Message Formats", highlight the "Default" format in the right pane and choose "Properties". On the "Advanced" tab of the "Default Properties" dialog, uncheck the boxes "Allow non-delivery reports". This will prevent NDRs from being sent to the Internet for incoming messages with invalid recipients.
