I ran the DNS test from http://www.dnsstuff.com/ on our mail server and I got this warning:Acceptance of NULL sender Mailserver rejected mail from the null  sender address. This is problematic because in many cases this means  important delivery status notifications may not be seen by anyone,  making many deliverability issues hard to diagnose.I have searched a lot about how to enable null senders using Exim but I cant find an information. Is this possible?
Allowing Exim to accept empty/null senders
exim