🚀 go-pugleaf

In article <334564be.3316659@news.demon.co.uk>, Andrew Clarke
<andrew@REMOVE-THIS.plinth.demon.co.uk> writes

>>Indeed, if you reject at MAIL FROM, some clients will resend :(
>
>Actually, as far as the punts are concerned there may be another
>problem.
>
>In the first version of the system, I returned a 501 to the MAIL FROM,

this means "syntax error" - not a good choice

>and the first time I tried it 'live' something seemed to go wrong
>badly somewhere.  I had two mail items on punt2, the first of which
>was to be bounced, the second rejected. Punt2 connected and got a 501
>to the first MAIL FROM at which point it RSET the session and
>disconnected. Fingering post showed that *both* items of mail had
>gone, and the second never re-appeared.

that does not seem correct. I would not be surprised if the first was
"bounced" (with a most unhelpful message) and the second was delayed
until some later connection.

>In the event I've modified it so that it flags a MAIL FROM as bad and
>will reject on the RCPT TO with a slightly modified 'mailbox unknown'
>return which makes it clear that the mail was rejected as a UCE
>avoidance measure.

this is generally felt to be "safe"

-- 
richard                      richard.clayton    @    T U R N P I K E .com
                                                     tel: +44 1306 732300
"Assembly of Japanese bicycle require great peace of mind" quoted in ZAMM