Ok I think I'm getting a handle on this:
In a user's .forwadr file:
#Exim Filter
pipe "/path/to/mailfilter email@???"
This will give the email for the user to STDIN of /path/to/mailfilter with email@??? as /path/to/mailfilter's argument?
Correct?
Ok, Reading the docs it says stuff about delivery doesn't happen until this or that and the importance of return codes.
So my question is if I exit(1); from /path/to/mailfilter (a perl script) then that tells exim that the pipe failed and the message goes to the black hole and is never heard from again, and if I exit(0); then it tells exim the pipe was successful and to continue on.
Correct?
Now the question is this:
How would I get Exim go ahead and deliver the message that /path/to/mailfilter creates instead
of the original message on an exit(0);?
TIA