Does GMS support white lists?
A white list is typically a list of IP addresses from which connections should be allowed. This is typically used to prevent people abusing your mail server by spamming it.
The option GMS Anti-Spam allows you to specify which IP addresses may connect to your server.
GMS Mail provides the option to limit the number of simulatenous connections from any IP address (this helps to prevent denial of service attacks).
Keywords:white list IP address banning