Reject spam from "email_that_does_not_exist"
The problem:1) I set SMTP record in my mailing software to mail.openrelay.com (example) which is open relay, so i can use it without authorization
2) I set FROM: and REPLY-TO: to "email_that_dosnot_exist@domain.com"
Now i can send spam and almost nobody can trace me back.
The question: how to protect my server from such connections on smtp level? I want to block all email messages from fake addresses before receiving the mail by the server. Is it possible? I have spent 2 days to find sutable solution, but no luck

Is it possible with Exim 4x?
http://www.exim.org/exim-html-4.00/d...l/spec_37.html
thank you.