Here's a spam filter with a different approach--it looks at the recipient to determine whether a message is spam. Abaca Technology's ReceiverNet service examines the header of each email message that passes through any Abaca email gateway. ReceiverNet uses a mathematical formula to determine a recipient's reputation (i.e., as a high, medium, or low-spam receiver) based on the messages that recipient receives and classifies messages as spam if similar messages have been sent to high spam receivers. ReceiverNet is hosted by Abaca over the Internet, and all Abaca email gateways deployed at customer locations communicate with it, so the service is using a large and growing pool of users to make its determinations about receiver reputations and spam messages.

Leo Jolicoeur, Abaca CEO, said that the company has been selling its Email Protection Gateway (appliance) and Virtual Email Protection Gateway (software that runs on VMware) for only a few months, but that the products are already identifying spam with a higher accuracy rate than its competitors. The company guarantees its customers 99 percent accuracy. Joicoeur and Director of Business Development Bill Kasje also emphasized the gateways' "near-zero" administration and easy-to-use quarantine interface for users as selling points for small-to-midsized businesses (SMBs).