Yes, everyone is correct that I called a challenge-response
incorrectly as greylisting. Sorry about that. Greylisting on CG Pro
however is implemented a little differently... I can adjust the
initial SMTP response time so it isn't specific to a user but
accomplishes the same thing. Regardless of challenge-response or
greylisting, or SMTP response delay, the idea is the same...
legitimate email is passed after a time delay. My idea was to remove
the time delay and in the course of normal email communications
between known and accepted contacts, improve the chances of mail
delivery without any delay or user interventional action.
I realize also that signatures can be excluded in responses, but they
don't have to be included in every response for the method to be
effective. The likelihood is for the common user that they WILL get
their signature with the private keyword sent back to them at least
from time to time in the course of routine email conversations with
their friends and contacts.
The autowhitelisting is indeed an averaging system, but that really
doesn't matter if the private keyword has a substantially negative
score. You would expect routine contacts occasionally sending the
private keyword back in their responses to always keep a
substantially safe negative score to always be in the 'white.'
Ron
On Dec 17, 2006, at 8:47 PM, John D. Hardin wrote:
That's not "greylisting", that's "challenge-response", and most agree
it is evil.
Greylisting is where your MTA tells a client "go away for fifteen
minutes" the first time a client connects and attempts to send a
message. This works fairly well against simpler bulk mailers that spew
messages as quickly as possible to an address list and don't attempt
to retry failed deliveries.
