Postfix/Rejecting_over-quota_during_SMTP_transaction_with_LDA

From http://archives.neohapsis.com/archives/postfix/2009-10/0956.html

Dovecot LDA doesn't reject during SMTP session and generates a bounce, would prefer to reject instead.

Another user mentioned http://mundoopensource.blogspot.com/2009/09/utilizando-o-postfix-quota-reject-20.html , see thread for details.

* Marty Anstey <marty.ansteysunwave.net>:
> Hi all,
> I have a quick question which relates to how Postfix interacts with LDAs
> (in particular, Dovecot).
>
> I've asked this question over on the Dovecot list, but it sounds like
> the issue is with how Postfix handles the response from Dovecot's LDA.
>
> When Dovecot's LDA (deliver) gets handed a message for a mailbox which
> is over quota, it exits with EX_NOPERM. Postfix sees this and generates
> a bounce.
>
> While I realize that this is perfectly acceptable behaviour, I've been
> asked to look into the possibility of having messages rejected inline
> during the SMTP session.
>
> Does anyone have any insight on how we could make this happen?

IIRC Wolfram <http://wolfram.schlich.org/> has been working on some code that
does exactly what you are looking for. I don't know which state his project is
in. Look for yourself.