Auto-response rules are used to automatically send email responses to lead or case submissions based on the criteria you define. You can create one auto-response rule per object (lead or case) and configure multiple rule entries with different criteria and actions within that rule. To meet the requirement of sending different email notifications based on case priority, you need to create one auto-response rule for cases and configure three rule entries with filters for low-priority, medium-priority, and high-priority cases respectively. Then you need to select the appropriate email template for each rule entry action. Reference: https://help.salesforce.com/s/articleView?id=sf.customize_leadsautor.htm&type=5 https://help.salesforce.com/s/articleView?id=sf.customize_casesautor.htm&type=5