I have a somewhat unique requirement here for one test that we're going to perform. I need to block relaying for a specific sender.
Only thing I could think of is control/badmailfrom.
That won't work - in this case ANY email from this sender will be blocked. But I only need to disable relaying, while allowing the sender to send email to local recipients.
And to be clear, by "sender" I mean the envelope sender.
