Simple rule to stomp on falsely self-addressed spam

[David Brown]

On Sun, Dec 07, 2008 at 01:32:23PM -0800, Andrew Lentvorski wrote:
>
>> [root at ista /usr/local/etc/postfix]# cat helo_access.cf
>> *.randomlogic.net       REJECT You are not me!
>> 216.75.6.67             REJECT Spoofed IP!
>> 134.17.0.0/16           REJECT Spammer!
>
> Aha!  I get it.  That's just blocking things that lie in the HELO line.  
> Got it.
>
> That's not *quite* what I want.
>
> What I want is for something that purports to be from domain mydomain.com 
> in the "DATA FROM:" line to do a quick match against the IP that is 
> currently connected and reject if not one of mine.

Would SPF help you?
<http://en.wikipedia.org/wiki/Sender_Policy_Framework>

One possibly way of doing it: <http://www.howtoforge.com/postfix_spf>

It also detects and rejects mail from any other participating domain
sent from an invalid host.

David