Milter-greylist

Matthias Scheler wrote:
> On Mon, Oct 17, 2005 at 10:45:35AM -0400, Matt Kettler wrote:
> 
>>Matthias, how does that help against a dictionary attack?
> 
> 
> Very well.
> 
> 
>>You can't put all possible combinations of username into /etc/mail/access.
>>The access list would be infinitely large.
> 
> 
> You whitelist valid e-mail addresses and blacklist everything else:
>>From the automatically generated part of my "/etc/mail/access":
> 
> To:tron@...			RELAY
> To:postmaster@...			RELAY
> [...]
> To:colwyn.zhadum.de				error:5.1.1:550 User unknown

Fair enough. That's workable, although cumbersome.

Do you have any suggestions that would work without having to maintain two
separate userlists? Adding this to /etc/mail/access is more-or-less the same as
using milter-rcptfilter as Emmanuel suggested.

Really, I'd be more interested in suggestions for how to change when
milter-greylist gets called by sendmail, so it happens after recipients are
validated.