I'm trying to clean up an Exchange server that I did not set up, and it's been quite a long time since I had to administer an e-mail server
I noticed just recently that if someone sends an e-mail to a non-existant user at our domain, they do not receive an NDR stating this. This can be a problem, especially for our sales department, because the sender will not know that their e-mail did not go through if they mistype an address; this could result in a lost sale.
Additionally, when I look at all the outbound e-mail sent by the postmaster account, there are a TON of NDRs being generated, but none of them ever make it past the "Submitted to categorizer" stage. There is nothing in my badmail folder.
So I'm wondering:
1. How do I set up Exchange to cause an NDR to be sent to the sender when they send to an invalid address? My preference is not for our server to generate the NDR, but to have the sending server generate it. This way we should be protected from spammers using NDRs to deliver their messages, no?
2. Where are all these NDRs from the postmaster account that are shown in message tracking going?