Orfila, AgustínCarbó Rubiera, Javier IgnacioRibagorda Garnacho, Arturo2012-02-032012-02-032004-11Information & Security, An international journal, 15(2), 151-1611311-1493https://hdl.handle.net/10016/13203One of the security challenges of e-Government is to offer a fluid dialogue to citizens that guarantees the availability, confidentiality and integrity of the information interchanged. Spam jeopardizes the sur- vival of electronic mail as a communication mean. Many approaches to solve the spam problem has been proposed. This paper shows the ne- cessity of studying the real value of spam filters. Contrary to common belief, false positive rate and false negative rate do not completely reveal to what extent a junk filter is worth using. Very important parameters like the hostility of the environment (summarized by the probability of receiving spam) or the error costs associated with the filter play a decisive role.application/pdfengAtribución-NoComercial-SinDerivadas 3.0 EspañaSpam DetectionDecision AnalysisFalse NegativesFalse PositivesNetwork SecurityBlacklistsresearch articleInformáticaopen access1512aInformation & Security, An international journal15