gwia intruder detection

Having problems with accounts getting locked from the GWIA. We a running GW 14.2.2 on OES 11 sp3. I found this Perl script that I'm try to get working on our GWIA to block ip address from failed login attempts.( It acts like it works but it does not put any ip address in the SuSEfirewall2-custom file. Here is the output when I run it,
SuSEfirewall2: Setting up rules from /etc/sysconfig/SuSEfirewall2 ...
SuSEfirewall2: Firewall customary rules loaded from /etc/sysconfig/scripts/SuSEfirewall2-custom
SuSEfirewall2: Warning: ip6tables does not support state matching. Extended IPv6 support disabled.
SuSEfirewall2: batch committing...
SuSEfirewall2: Firewall rules successfully set
I not sure if it is the Waring that is making it not work. Has anyone ever used this script to stop brute forcing password on the GWIA, or a better way. This GWIA is for our end uses that still use IMAP and SMTP and is on port 587, our main GWIA is not open to the world and gets in and out mail from our email scanner. Our user get lockout many time during the day and they are getting frustrated.