In this report the objective is outsourcing of spam filtering to other machines in order to save resources. Doing this is accomplished by using trust management and Bayesian networks. Trust management is analyzed in order to model aspects regarding trust in the Bayesian networks. A system, TrustOne, making outsourcing of spam filtering possible is designed, in which decision making is handled by Bayesian networks incorporated with trust management. Thus being able to handle risks and specify the confidence required to trust a machine to do spam filtering on the behalf of another machine. The resulting system encircle the source of the spam with machines running spam filters, by using outsourcing of spam filtering. This results in less network bandwidth usage and less resources used on machines in order to run spam filter.