Re: [AMaViS-user] Forged addresses and avoiding backscatter (was Re: Backscatterer.org, how to deal with?)

[Michael S. <sch...@se...>]

On 4/9/10 1:33 PM, Rodolfo Gonzalez Gonzalez wrote:
> Hello,
>
> Michael Scheidell wrote:
>    
>> amavisd can be configured to only bounce back if spf/dkim signed.
>>      
>
> How can be this done?
different issues, and I thought amavisd-new had an 'auth bounce limit' 
but I can't find it now.
> I'm also getting a lot of spam from forged
> addresses in my domain, most of it being stopped by DNSBL checks at
> postfix, but some high percentage of those spam messages still pass
> those checks. I use $final_spam_destiny = D_REJECT, which is supposed to
> send a 500 message back to the server,
doublecheck that.  that only works if you have amavisd-new in 'prequeue' 
(eg milter) mode.
read amavisd.conf-sample

> 1) If the message from my domain is dkim signed and optionally from a
> SPF allowed host, then it is passed.
>    
Use your MTA to send it to a different port using a different policy.

> 2) If it's not dkim signed or SPF allowed then it gets bad points and it
> is checked for additional spam characteristics and finally rejected.
>
>    
amavisd-sa already would do this.

> How could be this achieved? Any hint is appreciated.
>
> Thanks,
> Rodolfo.
>
>
> ------------------------------------------------------------------------------
> Download Intel® Parallel Studio Eval
> Try the new software tools for yourself. Speed compiling, find bugs
> proactively, and fine-tune applications for parallel performance.
> See why Intel Parallel Studio got high marks during beta.
> http://p.sf.net/sfu/intel-sw-dev
> _______________________________________________
> AMaViS-user mailing list
> AMa...@li...
> https://lists.sourceforge.net/lists/listinfo/amavis-user
>   AMaViS-FAQ:http://www.amavis.org/amavis-faq.php3
>   AMaViS-HowTos:http://www.amavis.org/howto/
>    


-- 
Michael Scheidell, CTO
Phone: 561-999-5000, x 1259
 > *| *SECNAP Network Security Corporation

    * Certified SNORT Integrator
    * 2008-9 Hot Company Award Winner, World Executive Alliance
    * Five-Star Partner Program 2009, VARBusiness
    * Best Anti-Spam Product 2008, Network Products Guide
    * King of Spam Filters, SC Magazine 2008

______________________________________________________________________
This email has been scanned and certified safe by SpammerTrap(r). 
For Information please see http://www.secnap.com/products/spammertrap/
______________________________________________________________________