At 09:27 AM 5/22/2005, guenther wrote:
On Sun, 2005-05-22 at 07:03 -0600, The Doctor wrote:
> How can one use user_prefs to tell spamassassin to reject spam
> tagged at level N at just send it back to them?
You can't.
SA is not designed to delete, deliver or bounce mail. It is designed to
scan and identify SPAM only. Any action taken (like delivering or
deleting) based on SA's judgment is another apps duty.
Besides, bouncing SPAM is not good practice. You'll often hit accounts
that are not in use at all or by innocent third party. Let your MTA or
MUA move them to a dedicated SPAM box or simply delete them, if you are
really sure not to get false positives.
Bouncing spam (sending it back after delivery) is a bad idea, and I will
outright blacklist the entire domain of anyone who sends me back a spam
forged in my name after detecting that it's spam, no questions asked.
That's horribly bad practice, and I view it as an intentional contribution
to a DDoS attack.
Unlike bouncing, rejecting spam (at the SMTP layer before accepting the
DATA command) is perfectly reasonable.
However, performing a reject is outside of spamassassin's abilities. SA is
designed to be very generic so it can be used at the MTA, MDA or MUA level.
Part of accomplishing this is limiting SA to simply scanning and marking
the message.
Deciding what to do with the message needs to be done by the tool above SA.
So if you use a MTA layer integration that calls SA before completing the
SMTP data phase, that tool can implement a reject. If you're using
procmail, rejection is impossible, as you're already at the MDA and the
SMTP transfer is long since done and over with.
If you want to do rejection (not bouncing) you'll need to choose an MTA
integration that closely couples to your MTA and can correctly issue a
reject. There are several different tools that do this, such as mimedefang
for sendmail and qmail-scanner for qmail. But each of these tools is
specific to one MTA, and there aren't any that I know of that work for
multiple different MTA packages (i.e.: Sendmail, Exim, postfix, and qmail.)
