https://docs.servicenow.com/bundle/tokyo-servicenow-platform/page/administer/notification/task/t_CreateANotification.html Reference:
An Email Notification is a record that defines the content and conditions for sending an email message from the ServiceNow platform. The following are configured in an Email Notification:
Who will receive the notification. This is specified by the Recipients related list, which can include users, groups, email addresses, or scripts that return email addresses.
What content will be in the notification. This is specified by the Subject and Message HTML fields, which can include variables, scripts, or templates to dynamically generate the email content.
When to send the notification. This is specified by the When to send tab, which defines the conditions and events that trigger the email notification.
The following is not configured in an Email Notification:
How to send the notification. This is not a configuration option for an Email Notification. The platform uses the SMTP protocol to send email messages, and the email properties control the email server settings and behavior. Reference: Email Notifications, Get Started with Notifications