#!/usr/bin/zsh --
# Program that delays mail files, to catch bulk-spam before it is send.
# This script reports on possible SPAM (bulk-mail from one user)
#
# Program released under the terms of the GNU GPL3.
# This is free software. You are free to copy and redistribute.
# No warranty. See http://www.gnu.org for license details.
# (C) 2007 Jos Boersema
#
# Usage: prog MAIL_FILE [exim4in|headers|RECIPIENTS]
# Manual:
#        Configure user-variables
#            -> mkdir a spool-directory for spam-delay,
#               same as in maildlay-input
#            -> configure an email adress to send warnings to
#            -> configure the amount of mails / user to send a
#               warning
#        Operation: cron job

########################################################################
#######             USER VARIABLES                          ############
########################################################################

# Set this to a directory that acts as a temporary bulk-spam delay buffer.
#SPAM_DELAY_SPOOL="/var/spool/mail/antispamdelay"
SPAM_DELAY_SPOOL="/tmp/antispamdelay"

# Temp file for spam-report
SPAM_REPORT_TMP="/tmp/spamdelayreport.temp"
SPAM_REPORT="/tmp/spamdelayreport"

# Set a warning-limit, when one user has more mails then this, mail
# a warning to ${WARN_EMAIL_TO}
WARN_LIMIT=200

#Email adress to send warning to
WARN_EMAIL_TO=nospam@someadmin.org

########################################################################
#######                  END                                ############
########################################################################

# Make a count of all mails for each user
cd "${SPAM_DELAY_SPOOL}"
echo -n "" > "${SPAM_REPORT_TMP}" # empty
for FROMUSER in $( ls -1 | sed -e 's/_Bye__.*//;s/_[0-9]*__.*//;' | uniq )
	do
		VAL=$(( $( ls ${FROMUSER}_* | sed -e "s/^${FROMUSER}_//;s/Bye/1/;s/__.*//;s/$/ +/;" | sed -e '$s/ +//;' ) )) 
    echo "${VAL}  ${FROMUSER}" >> "${SPAM_REPORT_TMP}" #note `  '
  done

#sort most first
sort -rn "${SPAM_REPORT_TMP}" > "${SPAM_REPORT}" 
HIGHEST="$( head -1 "${SPAM_REPORT}" | sed -e 's/  .*//;' )" #note `  '

echo "maildlay: highest number of mails: $HIGHEST"

if test "${WARN_LIMIT}" -le "${HIGHEST}"
	then
		echo "maildlay: send warning to ${WARN_EMAIL_TO}"
    head "${SPAM_REPORT}" | mail -s "maildlay: user with ${HIGHEST} mails, $( date )" "${WARN_EMAIL_TO}"
fi