handling spam from gmail.

[Ralph Seichter]

* Andreas Born:

> I meant the different stages when receiving mails over SMTP [...]

I am well aware of the technical details of SMTP. Your comment is
unclear to me because the OP did not make any limitations on when he
wants to counter spam, so why would we artificially limit ourselves in
this discussion? SMTP allows rejecting messages even after the whole
body has been received (end of DATA phase in SMTP, EOM phase in the
milter protocol).

> for many years it was code of practice to send error/rejection codes
> latest after the RCPT TO command [...]

Can you name examples? I have never used a milter so restricted, nor
have I seen one being used.

> Rejecting a mail AFTER the DATA command (when the content becomes
> available) was discouraged because of incorrect behaving
> MTAs. (e.g. generating backscatter, or even treating the mail as
> successfully sent)

Again I am stumped by what you write. SMTP rejection does not generate
backscatter. Frankly, I see no use in discussing broken MTAs or milters,
real or imagined. Using milter-regex and other milters with Postfix
works fine as I described it. What you wrote therefore makes little
sense to me.

-Ralph