[Greylist-users] Using a spam-trap e-mail address with greylist

[Bob Beck]

* Christopher Baker <chris at chrisbaker.net> [2007-03-10 07:23]:
> > At 05:05 PM 1/25/07, Dennis Wynne wrote:
> > >Say I make up a new, bogus user for our domain and post it on various web
> > >pages, online sites, newsgroups, etc but never use it for mail. Then I would
> > >automatically black list any IP that sends an e-mail to that user since it
> > >has to be from a spammer.
> > 
> > 
> > OpenBSD calls this "Greytrapping"; included since 3.7 (May 2005).
> > 
> > http://www.openbsd.org/cgi-bin/man.cgi?query=spamd&sektion=8
> > http://www.openbsd.org/cgi-bin/man.cgi?query=spamdb&sektion=8
> > 
> > When a host that is currently greylisted attempts to send mail to a 
> > spamtrap address, it is blacklisted for 24 hours 
> 
> Just 24 hours? You could make it more like a month.
> 

	No, all that means is it's now got dead information in the
list on which IP's were part of a botnet a month ago :)  I don't
want to have to manually maintain the list. 24 hours is more than
enough for them to either go away, or get themselves back in the 
blocklist again the next time :) 
	
	The other nice thing I actually use with this is 
the ability to greytrap whole domains (recently added for the
upcoming 4.1 release) - this is pretty darn handy if you've
got a site with zillions of old hosts that used to recieve mail
but don't anymore. MX them to the thing with the OpenBSD spamd
box in front of them and watch them hit the wall.

	-Bob <beck at openbsd.org>