On Sun, 22 Mar 2020, Florian Weimer wrote: > > Spam bouncing is evil and often hits an innocent person whose address has > > been faked by the sender of spam, making the source of bounces not better > > than the originator. > > I expect this to be an SMTP-level rejection, not a bounce. sourceware > generates a bounce from that, and Mailman reacts to that. But the > target mail server does not generate a bounce. So your concern about > bad ISP behavior does not apply here.
You mean as with a failure response given to the SMTP DATA command? This is actually equally evil as the resulting bounce (i.e. a delivery failure notification, or a flood of them, once other MTAs have joined in a response to a mass mailing; that is exactly what I suffered from a few years ago) will hit whoever's fake envelope sender address has been given with the MAIL FROM command. You don't expect a real one with spam, do you? As I say, just silently drop it on the floor, this is the least harmful way of dealing with spam. And sometimes indirectly blocking a specific e-mail address chosen to look like a source of spam *will be* the actual objective of what looks like usual spam. Maciej
