Which type of machine learning algorithm would be used to train a system to detect spam in email messages?

The type of machine learning algorithm that would be used to train a system to detect spam in email messages is classification. Classification is a type of supervised machine learning algorithm used to classify data into predefined classes. In the case of detecting spam in email messages, the algorithm would be trained on a labeled dataset of emails that have been classified as either spam or not spam. The algorithm would then learn to recognize patterns and features in the email messages that indicate whether they are spam or not. Once trained, the algorithm could be used to classify new, unlabeled email messages as either spam or not spam with a high degree of accuracy.