I'm running ISPConfig3 on my server, and I'm looking into the possibility of automatically processing undelivered emails with a script, if possible PHP. So I've been looking through the /var/vmail/ directories and the incoming mail is easy enough to detect, allright. So I would like to run a PHP cron that looks through the mailbox and does "something". Ideally, I would like to remove the bounced messages from the mailbox. But I could not find any description of the mail server's (is it postfix?) behavior, and if removing a message was as simple as just deleting it from the /new directory? Is there a description of postfix somewhere?