Re: [exim] First time SMTP connection with "temporary error"…

Heron wrote:
> Hi,
>
> I have pointed out that some SMTP servers in the world reject incoming
> e-mails for the first time with a "temporary error" message. If the message
> comes second time it is accepted.
> This mechanism is used to reject many spams, since many spam sending
> computers do not try to send the message again after receiving "temporary
> error" message from the remote SMTP server.
>
> My question is - how to implement such mechanism in Exim 4.x ?
>
>

Hi Robert,

The keyword for this technique is "greylisting" / "graylisting". Take a
look at http://www.greylisting.org/

Peter