Milter-greylist

On Mon, Mar 14, 2005 at 12:50:26AM -0500, Uriel Wittenberg wrote:
> Why is notification impossible when deleting previously accepted messages as 
> I suggested? Why not:
> 
> - ISP receives a message for user
> - sender address appears on blacklist an hour later
> - ISP rejects THEN, with notification

Because at that time, you accepted the message, and the only way to 
send a notification is to trust the sender address. And you know this is
forged most of the time.

> Also, if you're assuming the blacklist is unreliable, then why did you 
> write:
> >I'd rather see [black list filtering done] at the MUA (Mail User Agent,
> >outlook express in your case) level.

Because at the MUA level, the user can review the operation. The MUA could
use DNSRBL to tag mails as probably spam and the user can delete or not.

> I also don't understand why automatically updated blacklists should 
> generally be unreliable. When do legit addresses send email to honeypot 
> addresses?

Some spammers spam through ISP SMTP servers, causing all this ISP customers
to be in blacklist. 

Moreover, a spammer that discovered a honeypot could work on poisonning 
the honeypot.

-- 
Emmanuel Dreyfus
manu@...