Disclosed is a system and method for selective email processing. A traffic separator includes an interface for receiving electronic mail traffic from a source network address. The traffic separator also includes a processor for comparing the source network address to a stored list of network addresses to determine a categorization of the network source address. The traffic separator also includes at least one interface for forwarding the electronic mail traffic to one of many message transfer agents (MTAs) based upon said determination. A database stores the list of network addresses. In one embodiment, one or more network addresses in the stored list are network address ranges.