A Silicon Valley startup has introduced a new email service that aims to address the problem of email spam. The startup wants to be extra sure that genuine emails are not marked as spam. The underlying machine learning model’s predicted value of 1 implies that the model predicts a given email to be spam. The data scientists at the startup would like to analyze the results of the underlying model. As an AWS ML specialist, which of the following would you identify as the most important evaluation metric for this model?