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

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 ?


Robert Heron