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.