Re: [Exim] Avoiding frozen spam

On Wed, 8 Oct 2003, Giuliano Gavazzi wrote:

> forged addresses (mainly because some providers still do not check
> their local recipient at smtp time. e.g. yahoo).

In the interests of accuracy: yahoo sometimes do, and sometimes don't:

response to "RCPT TO:<OBFUSCATED@???>" from mx2.mail.yahoo.com
[64.156.215.5] was: 553 VS10-RT Possible forgery
or deactivated due to abuse (#5.1.1)

We reject a modest amount of spam per day by that means.

NB: we only do callbacks for domains which we've listed locally, and
we don't list them until we've seen some prospect of the relevant MTA
actually rejecting mail at RCPT time.