John Peach wrote:
On Mon, 16 Nov 2009 13:07:05 -0700
Jim Lang <post...@guscreek.com> wrote:
John Peach wrote:
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.
I must have been really inarticulate when I wrote out the scenario.
I do use recipient verification on my server. How is it that that is
not clear? Do I need to rewrite this post?
Clearly, you are *NOT* doing recipient verification, or
myotherserver.com would not be rejecting it. Never accept mail which
cannot be delivered.
Except no 'myotherserver.com' appeared in my scenario, nimrod.
otherserver.com in the scenario is a server not under my control.
unsubcribing to this useless list
