Milter-greylist

Manu and guys,
Sorry, I feel that I am too chatty today.  I promice to stop after
this message ;-)

I've got another idea how to measure rating of the peer, this time
completely within existing infrastructure.  The idea is this:

if a greylisted submission was *not* retried by the peer within, say,
12 hours, the peer is likely no good!  Good guys always retry after 4xx.

One caveat: the peer might have resent the message via anotehr MX.  So
reception of the same (sender, recipient) from one of our MXes should
amnesty the original sender address.

How does it sound?

Eugene