On T 20 Jan, 2009, at 12:38 , Steffen Kaiser wrote:
So you can hack sendmail. Exim, too, if I remember correctly.
I would not call that hack in exim case though. It is possible to avoid all backscatter, first of all by avoiding delivery by an external programme*. This will still leave the possibility of a failure in forwarding, but by changing the envelope sender to the local administrator address (setting errors_to in the delivering routers) even a failure in forwarding will only cause a locally delivered failure report. There is no excuse for backscatter and whoever causes it will likely and rightly end up in some blacklist, local or distributed, sooner or later.
Giuliano
