Patent ID: 7606214

Claim:
A method of performing anti-spam in a router in a computer network, the method comprising: receiving in the router a TCP handshake packet from an initiating mail transfer agent, the TCP handshake packet being configured to initiate a connection with another mail transfer agent; detecting receipt of the TCP handshake packet in the router; determining an IP address of the initiating mail transfer agent; consulting an externally located network reputation service to determine if the IP address belongs to a known spammer; inspecting at a network layer a source IP address of an IP packet received in the router; and performing a predetermined action on the IP packet in the router when the source IP address is that of the initiating mail transfer agent and the mail transfer agent is deemed by the network reputation service as belonging to a known spammer, wherein the predetermined action includes marking the IP packet as low priority as part of slowing down a data transfer rate of all packets from the initiating mail transfer agent.