Milter-greylist

Matthias Scheler wrote:
> On Fri, Apr 07, 2006 at 04:57:02PM +0200, Michael Menge wrote:
>> I think SPF (see www.openspf.org)  may be a googd idea to use.
> 
> SPF is quickly becoming worthless because spammers register new domains,
> create fine looking SPF records for their spam bot networks and start
> delivering spam from them.

Duh.. this is exactly what SPF is intended to do.. Force spammers to create
their own domains instead of abusing existing ones.

Anyone who thinks SPF is intended to stop spam is fooling themselves. SPF is an
anti-forgery technology. This has some utility in fighting spam, but it isn't
intended to stop spam.

Also on the upside for the spam front, forcing spammers to create their own
domains costs them money.
> 
> I'm currently using SPF for automatic white listing in Milter Greylist
> and am seriously considering to drop it.

You really should. IMHO, this is one of the most misconceived features of
milter-greylist. Passing SPF is a horribly poor indication the message is in any
way "good" from a spam perspective.

In general the only thing you can treat with much credibility on the spam front
is treating SPF failures as an indication the message is likely spam. Period.

really, milter-greylist should generalize SPF results into ACL rules, so we can
all choose what to do at different SPF levels.

This way we can do things like this:

acl spf_softfail dark_greylist
acl spf_fail blacklist
acl default greylist

which makes a lot more sense than the current use of SPF in milter-greylist.

(note- read the dark-grey thread for the idea behind dark_greylist)