3. The method of claim 1 , wherein the space of possible classifiers is represented by a set of parameterized weights and basis functions, and the optimization procedure searches the parameterized weight space to identify the combined spam classifier for which the given penalty function is minimal on the labeled e-mail corpus.
3. The method of claim 1 , wherein the space of possible classifiers is represented by a set of parameterized weights and basis functions, and the optimization procedure searches the parameterized weight space to identify the combined spam classifier for which the given penalty function is minimal on the labeled e-mail corpus. 6. The method of claim 3 , wherein the basis functions are fixed transformations of individual output scores of the constituent spam classifiers.