1. A method for processing electronic mail comprising: receiving at a network interface electronic mail traffic; inspecting, at a processor, an internet protocol header of the electronic mail traffic to determine a source network address associated with the electronic mail traffic; identifying the source network address as an untrusted source, based on comparing the source network address to a stored list of network addresses and based on a threshold and a percentage of unknown recipients associated with the electronic mail traffic; assigning a trust level to the source network address, wherein the trust level is selected from a plurality of trust levels and is assigned based on the electronic mail traffic, the stored list of network addresses, the threshold and the percentage of unknown recipients associated with the electronic mail traffic; identifying one of a plurality of message transfer agents, each of the plurality of message transfer agents having an amount of resources, wherein the resources allow for each of the plurality of message transfer agents to be configured to performance levels associated with the plurality of trust levels, the identifying based on the trust level assigned to the source network address and an amount of resources of the one of the plurality of message transfer agents; wherein the resources comprise a number of transmission control protocol connections; in response to identifying of the source network address as an untrusted source, forwarding the electronic mail traffic to the one of a plurality of message transfer agents; and performing virus filtering on the electronic mail traffic, wherein an amount of filtering performed on the electronic mail traffic is based on the trust level.