On Mon, 16 Nov 2009 13:00:26 -0700 Jim Lang <post...@guscreek.com> wrote:
> Wietse Venema wrote: > > Jim Lang: > > > >> OK here is the scenario. > >> > >> Spammer sends mail to: u...@myclientsdomain.com from forged > >> address vic...@randomdomain.com > >> > >> If u...@myclientsdomain.com is delivered locally, not a problem, > >> if the address is invalid, postix rejects the mail during the smtp > >> connection. > >> > >> But if u...@myclientsdomain.com is an alias to > >> mycli...@otherserver.com, postfix accepts the mail as deliverable > >> and forwards it to hotmail.com. > >> > >> But if mycli...@otherserver.com can for whatever reason not be > >> delivered, otherserver.com does what it is supposed to do and > >> rejects the mail during the smtp connection, which causes postfix > >> to send out a non-delivery report to vic...@randomdomain.com -- > >> backscatter. > >> > >> Is there a way to stop this? > >> > > > > Yes. Don't forward SPAM. > > > > Wietse > > > And how do I do that in this scenario? You use recipient verification. > > -- John
