Turning off status msgs groupwise 5.5SP5

Hi,
I have a problem with my GW5.5sp5 system where it is returning status messages to the sender even though I have it all turned off. Within my GWIA settings on the undeliverables tab I have both Move to problem directory and send to postmaster unchecked. Within my GWIA.CFG I have near the bottom of the file
/HN-MAIL
/NOROUTING
/BADMSG-NEITHER

Even with all of this off my system is getting so bogged down it doesn’t send any email out because it is so busy returning status messages to someone who is trying to relay spam through us. Why is this happening that it’s sending back messages even though I tell it not to and how do I turn it off permamently.
Thanks.
Pete