Batch Script default SMTP Server - Blacklist Check

#!/bin/sh
#
# dnsbl-check-standalone.sh
#
# By Damon Tajeddini (dta)
# # 10.03.2009
#

DNSBLlist=`grep -v ^# <<!
cbl.abuseat.org
dnsbl.ahbl.org
ircbl.ahbl.org
virbl.dnsbl.bit.nl
blackholes.five-ten-sg.com
dnsbl.inps.de
ix.dnsbl.manitu.net
no-more-funn.moensted.dk
combined.njabl.org
dnsbl.njabl.org
dnsbl.sorbs.net
bl.spamcannibal.org
bl.spamcop.net
sbl.spamhaus.org
xbl.spamhaus.org
pbl.spamhaus.org
dnsbl-1.uceprotect.net
# dnsbl-2.uceprotect.net
# dnsbl-3.uceprotect.net
psbl.surriel.com
l2.apews.org
dnsrbl.swinog.ch
db.wpbl.info
!`

# reverse IP address bytes
convertIP()
{
 set `IFS=".";echo $1`  
 echo $4.$3.$2.$1
}

usage()
{
 echo "Usage: $0 [-H <host>|-p]"  
 echo " -H IP address to check"  
 exit 3
}

# Checks the IP with list of DNSBL servers
check()
{
 for i in $DNSBLlist
 do
 if dig $ip_arpa.$i +short | grep -q "^127.0.0."  
 then
 echo ":$ip found on $i **"  
 fi
 done
 exit
} # check

case $1 in
 -H)
 if [ -z "$2" ]; then  
 echo "ip address missing"  
 exit
 fi
 ip=$2
 ip_arpa=`convertIP $ip`
 check;;

 --help)
 usage
 exit;;

 *)
 if [ -z "$1" ]; then  
 usage
 fi
 echo "unknown command: $1"  
 exit;;
esac