#!/bin/bash
#
# Procmail helper to bounce spam messages.
#
# Usage in procmail:
#
# :0
# * ^From .*\.spammer\.com
# * ^Received: .*\.provider\.net
# | spam-forward -s '[SPAM ALERT] Oops, they did it again' \
#      postmaster@provider.net
#

[ "$SENDMAIL" = "" ] && SENDMAIL=/usr/sbin/sendmail
[ "$SENDMAILFLAGS" = "" ] && SENDMAILFLAGS=-oi

subject='[SPAM ALERT]'
while getopts s: opt; do
    subject="$OPTARG"
done

shift $(( $OPTIND - 1 ))

dest="$*"
if [ -z "$dest" ]; then
    echo "Usage: $0 [-s subject] recipient ... <message" >&2
    exit 1
fi

to_line="${*/%/,}"
to_line="${to_line%,}"

(   cat <<EOF
From: $LOGNAME
To: $to_line
Subject: $subject
X-BeenThere: $LOGNAME@$HOST
Precedence: bulk
MIME-Version: 1.0
Content-Type: text/plain
Content-Transfer-Encoding: 8bit

Hello,

This is an automatically generated spam alert.
Feel free to contact me if you have any issues related to this.
The (partial) listing of the message that triggered it
is included below.


EOF
    head -c 8k
    cat >/dev/null
) | $SENDMAIL $SENDMAILFLAGS $dest