%0 Journal Article %J ACM Transactions on Information Systems (TOIS) %D 2008 %T Trusting spam reporters: A reporter-based reputation system for email filtering %A Zheleva,Elena %A Kolcz,Aleksander %A Getoor, Lise %K reputation systems %K Spam filtering %K trust %X Spam is a growing problem; it interferes with valid email and burdens both email users and service providers. In this work, we propose a reactive spam-filtering system based on reporter reputation for use in conjunction with existing spam-filtering techniques. The system has a trust-maintenance component for users, based on their spam-reporting behavior. The challenge that we consider is that of maintaining a reliable system, not vulnerable to malicious users, that will provide early spam-campaign detection to reduce the costs incurred by users and systems. We report on the utility of a reputation system for spam filtering that makes use of the feedback of trustworthy users. We evaluate our proposed framework, using actual complaint feedback from a large population of users, and validate its spam-filtering performance on a collection of real email traffic over several weeks. To test the broader implication of the system, we create a model of the behavior of malicious reporters, and we simulate the system under various assumptions using a synthetic dataset. %B ACM Transactions on Information Systems (TOIS) %V 27 %P 3:1–3:27 - 3:1–3:27 %8 2008/12// %@ 1046-8188 %G eng %U http://doi.acm.org/10.1145/1416950.1416953 %N 1 %R 10.1145/1416950.1416953