Milter-greylist

Oliver Fromme wrote:
> Hi,
> 
> First of all, thank you very much for creating milter-
> greylist.  It really helps a lot.
> 
> Now I've got a question.  My MX server gets a lot of
> probes from spammers for mail accounts that don't exist.
> That is, I have thousands of these in my logs:
> 
> Jan 20 00:01:19 [...] <guirre@mydomain>... User unknown
> Jan 20 00:01:19 [...] <gulfier@mydomain>... User unknown
> Jan 20 00:01:20 [...] <gullit@mydomain>... User unknown
> Jan 20 00:01:21 [...] <gummo@mydomain>... User unknown
> 
> After installing milter-greylist, all of those are
> greylisted:
> 
> Jan 20 13:17:44 [...] to <arioch@mydomain> delayed for 00:03:00
> Jan 20 13:17:56 [...] to <arjani@mydomain> delayed for 00:03:00
> Jan 20 13:18:33 [...] to <arkeen@mydomain> delayed for 00:03:00
> Jan 20 13:18:34 [...] to <arkosic@mydomain> delayed for 00:03:00
> 
> Those just take up space in the greylist for no reason.
> In fact, 99% of the contents of my dump file is from
> such useless probes.  And the address harvester might
> even come back and probe the same account again.
> 
> Is it possible _not_ to greylist those, but reject the
> mails permanently (and immediately)?  In other words,
> a permanent "User unknow" should take precedence over
> temporary greylisting.

I asked this a long time ago. Unfortunately, with the Sendmail Milter API this
isn't possible without changing to post-data-phase greylisting, which has a lot
of problems with excessive bandwidth consumption.


You can add on another milter to run ahead of milter-greylist. This is a little
silly, but unfortunately it's the only way to get user-validation before
greylisting.