A graymail detection and filtering system predicts whether a user will consider an email to be graymail using a classifier model based on features extracted from the email. The email is labelled as graymail or non-graymail based on the prediction. User actions are tracked on the email to determine whether the user actually considered the email to be graymail or non-graymail and the classifier model is trained using machine learning techniques to improve the prediction, without requiring explicit user feedback on whether the user considered the email to be graymail or non-graymail.