The way that a marketer can avoid emailing prospects more than once in a ten day span is to use a dynamic list to create a frequency suppression list. A dynamic list is a type of list that automatically updates based on specific criteria, such as field values, activities, or scores. A frequency suppression list is a type of list that excludes prospects who have been emailed within a certain time frame, such as ten days. By using a dynamic list with a frequency suppression criteria, a marketer can ensure that they do not email prospects who have already received an email recently. Using an automation rule, a global account setting, or a segmentation rule are not ways that a marketer can avoid emailing prospects more than once in a ten day span, as they either do not create lists, do not update automatically, or do not run continuously2. References: 2: Dynamic Lists