Excuse me, but why is this complicated?
While PRDR may be very useful, it isn't needed here. More
important, if the message really is spam, the odds that the
spammer will request PRDR seems to me to be slight to none...
and it might not be desirable to give the spammers that much
information if they did ask for it.
So you have
C: MAIL FROM:<spammer(_at_)example(_dot_)com>
S: 250 OK, I suppose
C: RCPT TO:<spamtrap(_at_)example(_dot_)org>
S: 250 Ok, amuse yourself
C: RCPT TO:<mailing-list(_at_)example(_dot_)org>
S: 550 As far as you are concerned, no such address
C: DATA
S: 354 Go
[...]
Is there something I'm missing?
john
--On Monday, 16 July, 2007 22:25 -0700 Claus Assmann
<ietf-smtp(_at_)esmtp(_dot_)org> wrote:
On Tue, Jul 17, 2007, Dilyan Palauzov wrote:
My use case is, that I want to accept a message partially
during the SMTP dialog. Imagine one mail with two
recipients, spamtrap(_at_)example(_dot_)org and
mailing-list(_at_)example(_dot_)org is coming to my server. I do not
want to accept the mail for mailing-list(_at_)example(_dot_)org, since
later it will be bounced, may end in a spamtrap and my
server will be blacklisted. At the same time I want to
accept the mail for (my) spamtrap(_at_)example(_dot_)org, in order to
improve my spam filter.
See:
http://www.ietf.org/internet-drafts/draft-hall-prdr-00.txt
MAIL FROM: spammer(_at_)example(_dot_)com
Wrong syntax:
MAIL FROM:<spammer(_at_)example(_dot_)com>
RCPT TO: spamtrap(_at_)example(_dot_)org
Same here.
250 OK
RCPT TO: mailing-list(_at_)example(_dot_)org
and again.
451 Try again later
That's the current way to deal with the problem if PRDR isn't
supported.
...