Is there any way to stop the spamming alert messages coming to the 
postmaster ??

We are running private lists and the the go.user file specifies 
runmode=standalone
I understood that this would remove our listserver from the global Listserv
systwem, and therefore we would not receive any further notifications.

I changed this over a week ago, but the spamming messages still keep 
coming, up to 100-200 per day.

Our system is entirely internal, and we do not require anti-spam messages.