3 Apr
2006
3 Apr
'06
13:38
Well, the only way to reject an email because it is considered spam is after complete reception; the scanning is surely done later. It is simply a «bad thing» to bounce back spam.
Just like you can reject on 'invalid user' or a RBL/RHSBL, you can reject on the content of a message. Point is, you have to do it before you have accepted the message for delivery. This has been possible with Sendmail for quite a while (via the Milter interface) and Postfix now also allows you to do this with the before-queue content filtering since version 2.1 (see smtpd_proxy_filter). Arjen