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
