#!/bin/bash

IN_REGEX='to=[^@]+@<?([^,>]+)[,>].*? mailer=virthostmail'
IN_USER_REGEX='to=<?([^>,]+).+mailer=virthostmail.*relay=\S+'
OUT_REGEX='from=[^@]+@<?([^,>]+)[,>].*? relay=localhost'
#OUT_REGEX='from=[^@]+@<?([^,>]+)[,>].*? relay=localhost.localdomain'
RELAY_OUT_REGEX='to=(\S+)\s.+\s+mailer=esmtp.+\s+relay=(\S+)'
RELAY_IN_REGEX='from=(\S+)\s.*? proto=E?SMTP, daemon=MTA.*relay=(\S+)'
BLACKHOLE_REJECT_REGEX='arg1=[\[<]?([^\]>, ]+).*?reject=553'
REJECTED_REGEX='reject=(\S+)'
REJECT_REGEX='relay=[\[<]?([^\]>, ]+).*?reject='
STAT_REGEX='stat=(\w[\w\s]+\w)\W'
ESTAT_REGEX='to=(\S+)\s?.+\smailer=(?:(?!virthostmail)\S+)\s.+relay=(\S+)\s.+\s+stat=(\w[\w\s]+\w)\W'
ESTAT_LOCAL_REGEX='to=(\S+)\s?.+\smailer=virthostmail,\s.+relay=(\S+)\s.+\s+stat=(\w[\w\s]+\w)\W'
DEFERRED_REGEX='to=(\S+)\s+.+stat=[Dd]eferred:\s*(.+)$'
POP3_REGEX='pop3.*?Login user=(\S+)\s+host=(\S+)'
IMAP_REGEX='imapd.*?Login user=(\S+)\s+host=(\S+)'

DAYS=""

MSG=""

HIDE_DEFERRED=0

for arg
do

    case $arg in 
       --in) REGEX=$IN_REGEX; MSG="Local virt hosts receiving mail"   ;;
       --in-user) REGEX=$IN_USER_REGEX; MSG="Local users receiving mail"   ;;
      --out) REGEX=$OUT_REGEX; MSG="Local virt hosts sending mail" ;;
      --blackhole) REGEX=$BLACKHOLE_REJECT_REGEX; MSG="Blackholed mail hosts" ;;
      --stat) REGEX=$STAT_REGEX; MSG="Mail status count" ;;
      --estat) REGEX=$ESTAT_REGEX; MSG="Extended status (mail relayed offsite)" ;;
      --estat-l) REGEX=$ESTAT_LOCAL_REGEX; MSG="Extended status (virtual host deliveries)" ;;
      --pop3-logins) REGEX=$POP3_REGEX; MSG="POP3 logins" ;;
      --imap-logins) REGEX=$IMAP_REGEX; MSG="IMAP logins" ;;
      --deferred) REGEX=$DEFERRED_REGEX; MSG="Deferred list" ;;
      --rejected) REGEX=$REJECTED_REGEX; MSG="Rejected mail count/status" ;;
      --rejected-relays) REGEX=$REJECT_REGEX; MSG="Rejected mail relays" ;;
      --transactions) FULL=1;;
      --minutes) shift; MINS=$1;
          let COUNT=$1;
          DATE=""
          while [ $COUNT -gt -1 ]
          do
              D="$(date  -d "-${COUNT} minutes" '+%b %e %H:%M')"
              if [ $COUNT -eq $MINS ]
              then
                  DATE="^($D"
              elif [ $COUNT -gt -1 ]
              then
                  DATE="$DATE|$D"
              fi
              COUNT=$((COUNT - 1))
          done
          DATE="$DATE)"

      ;; 
      --hours) shift; HOURS=$1;
          let COUNT=$1;
          DATE=""
          while [ $COUNT -gt -1 ]
          do
              D="$(date  -d "-${COUNT} hours" '+%b %e %H')"
              if [ $COUNT -eq $HOURS ]
              then
                  DATE="^($D"
              elif [ $COUNT -gt -1 ]
              then
                  DATE="$DATE|$D"
              fi
              COUNT=$((COUNT - 1))
          done
          DATE="$DATE)"

      ;; 
      --days) shift; DAYS=$1;
          let COUNT=$1;
          DATE=""
          while [ $COUNT -gt -1 ]
          do
              D="$(date  -d "-${COUNT} days" '+%b %e')"
              if [ $COUNT -eq $DAYS ]
              then
                  DATE="^($D"
              elif [ $COUNT -gt -1 ]
              then
                  DATE="$DATE|$D"
              fi
              COUNT=$((COUNT - 1))
          done
          DATE="$DATE)"

      ;; 
      --help) REGEX="";;
      --hide-deferred) HIDE_DEFERRED=1;;
      --relay-out) 
          REGEX=$RELAY_OUT_REGEX ; MSG="Relayed out from virthosts" 
          if [ "$HIDE_DEFERRED" = "1" ]
          then
              REGEX="${REGEX}.+stat=(?![Dd]eferred)"
          fi
      ;;
      --relay-in) REGEX=$RELAY_IN_REGEX ; MSG="Relayed in from other hosts" ;;
          *) DAYS="$DAYS $1"  ;;
    esac

    shift

done

DAYS=$(echo "$DAYS" | sed -e 's/^ //')

if [ -z "$DAYS" ]
then
    DAYS="0 days"
fi

if [ -z "$REGEX" ]
then
    clear
    cat <<EOF

USAGE: $0 command \\
       [ --minutes n | --hours n | --days n | date_specifier]

Where command is one of:
    --in:        Names/count of virtual hosts receiving mail
    --out:       Names/count of virtual hosts sending mail (e.g. via squirrelmail)
    --relay-out: To addresses of mail sent from virtual host via .forward, catchall, etc.
    --relay-in:  To addresses of mail sent TO this host
    --stat:      List of states mail sent by this machine elsewhere
    --estat:     List of to address, relay, and state tuples for mail relayed offsite
    --estat-l:   List of to address, relay, and state tuples for mail relayed to virtual
                 hosts (local relays)
    --deferred:  List of deferred outbound emails, with recipient name and 
                 reason for defer.
    --hide-deferred:
                 When used with --relay-out, hides entries for relay out
                 attempts that resulted in deferral.
    --blackhole: Host names/ips of sending hosts blocked by sendmail (status 553)
    --rejected:  Count of number of mails rejected, ordered by status
    --rejected-relays:  Names/IPs of sending relays blocked by sendmail
    --pop3-logins: Client email addresses/relays of POP3 logins
    --imap-logins: Client email addresses/relays of IMAP logins

Example usage:

$0 --in
#  Names/count of hosts rejected from sending mail to us in last 30 minutes
$0 --blackhole --minutes 30
#  To addresses for mail sent from our host via a .forward, catchall (outbound relay)
#  in last hour
$0 --relay-out --minutes 60
#  Names/count of rejected relays for yesterday
$0 --rejected-relays yesterday
#  Addresses/counts/reasons of deferred outbound emails over last 5 days
$0 --deferred --days 5
#  Outbound emails that were not succesfully sent offiste
$0 --estat | fgrep -v sent
#  Relayed out email, hides deferred delivery attempts
$0 --hide-deferred --relay-out

EOF
     exit 1
fi


if [ -z "$DATE" ]
then
    DATE="$(date  -d "$DAYS" '+%b %e')"
    PRETTY="$(date  -d "$DAYS" '+%m/%d/%Y')"
else
    PERIOD=""
    if [ "x$MINS" != "x" ]
    then
        PERIOD="$MINS minutes"
    elif [ "x$HOURS" != "x" ]
    then
        PERIOD="$HOURS hours"
    elif [ "x$DAYS" != "x" ]
    then
        PERIOD="$DAYS days"
    fi

    PRETTY="last $PERIOD"
fi

cat <<EOF

=================================================
$MSG for $PRETTY:
=================================================

EOF

ENTRIES="$(egrep "$DATE" /var/log/maillog* /var/log/secure* | \
    perl -n -e '
        my @matches = (/'"$REGEX"'/i);
        print join(" ",@matches,"\n")
            if @matches;
    ' |  tr 'A-Z' 'a-z' |  sort | uniq -c | sort -rn)"

if [ "$ENTRIES" = "" ]
then
    echo "No entries found in any mail logs for that date"
else
    echo "$ENTRIES"
fi

echo

exit 0