An electrophotographic printing apparatus and method are provided to separate particles of at least one toner color from a mixture of colored toner particles. If a determination is made that the at least one SMTP client application dirty page is a match and the at least one executable application dirty page, a determination is made that the SMTP client application is polymorphic malicious code that is attempting to send itself and protective action is taken. Each of the caps has a cavity therein. In turn, in some implementations, the information produced using the modified HAC process is sufficient to determine more a reliable detection threshold metric for detecting and matching the VSP as vocalized by the particular speaker. The bars are located in housings and form a monolithic structure with the housings respectively.