[Mimedefang] Can MD/SA combo detect no reverse ip?

[G. Roderick Singleton]

On Thu, 2003-06-12 at 09:10, Joseph Brennan wrote:
> --On Thursday, June 12, 2003 07:22 -0400 "G. Roderick Singleton" 
> <gerry at pathtech.org> wrote:
> 
> > I have been watching my logs for the past few days and find that there
> > is a bunch o' spam that gets trough with SA scores of less than the 5
> > threshold I use and most of these don't resolve to a reverse address
> > that is authoritative. I would like to block these and if possible block
> > dns lamers.
> 
> You'd be rejecting a lot of non-spam mail.  Some of the MSN mail
> servers lack reverse DNS, as an example; so do miscellaneous
> nonprofits and small businesses.  Remember the RFCs do not require
> rDNS for mail hosts.

I'll think about this. I am not overly concerned about MSN clients even
Non-profits that use this service. For non-profits there are other
services that are better suited. For example, http://www.torfree.net/ 
Even I am not certain that I want any unsubscribed solicitations.
However, one must start somewhere, so I will do as everyone has
recommended.

> 
> But you could add to the spam score.
> 
> In filter_begin()
> 
>     # Spamassassin tweaks using relay information
>     $SA_score_additions = 0;
>     $SA_test_additions = "";
> 
>     # Prejudice against no rDNS
>     if ($RelayHostname =~ /\[$RelayAddr\]/) {
>         $SA_score_additions += 2;
>         $SA_test_additions .= ",NO_RDNS";
>     }
> 

I like David's lower score better and will use that.

> 
> In filter_end(), add the score and test name right after you run
> Spamassassin, like this.
> 
>             my($hits, $req, $names, $report) = spam_assassin_check();
> 
>             # add our things
>             $hits += $SA_score_additions;
>             $names .= $SA_test_additions;
> 
> 
> The reason I did it this way was to use the $RelayHostname
> and $RelayAddr values that we get in Mimedefang.
> 
> Adding 2 is enough for us.
> 

Much obliged to all for a solution.

-- 
Gerry Roderick Singleton <gerry at pathtech.org>
416-452-4583