* Henning Brauer <[EMAIL PROTECTED]> [2007-05-23 11:48]: > * Bob Beck <[EMAIL PROTECTED]> [2007-05-22 23:45]: > > > just deduced from trial and error. Also greylisting should happen at > > > RCPT TO, and probably not at DATA as there are some widely used MTAs > > > that are buggy and choke when a 4xx error is sent in the DATA phase. > > > > I've been running this at DATA for months, and not seen any > > issues with it. > > > > anyone here got hard evidence of such bugs - please show > > me. Or is this just uninformed speculation? > > err, wait, are you giving a 4xx in reply to DATA? > that is invalid.
eh, I wanted to send that in private mail.. too late ;( rfc 2821 specifically forbids this behaviour. <quote> The DATA command can fail at only two points in the protocol exchange: - If there was no MAIL, or no RCPT, command, or all such commands were rejected, the server MAY return a "command out of sequence" (503) or "no valid recipients" (554) reply in response to the DATA command. If one of those replies (or any other 5yz reply) is received, the client MUST NOT send the message data; more generally, message data MUST NOT be sent unless a 354 reply is received. - If the verb is initially accepted and the 354 reply issued, the DATA command should fail only if the mail transaction was incomplete (for example, no recipients), or if resources were unavailable (including, of course, the server unexpectedly becoming unavailable), or if the server determines that the message should be rejected for policy or other reasons. </quote> -- Henning Brauer, [EMAIL PROTECTED], [EMAIL PROTECTED] BS Web Services, http://bsws.de Full-Service ISP - Secure Hosting, Mail and DNS Services Dedicated Servers, Rootservers, Application Hosting - Hamburg & Amsterdam