DSN, or Delivery Status Notification, is an important term used in the email communication world. DSN is an automatic notification email sent to the sender regarding the email delivery status - whether it has been delivered, delayed or failed. The term DSN is commonly used synonymously with "Return Receipt" or "Read Receipt" that are features commonly found in email clients like Gmail or Outlook. In addition, DSN can also be referred to as "Delivery Receipt" or "Disposition Notification". While these terms have slightly different meanings, they all ultimately convey the same message regarding the status of an email. It is important for email senders and recipients to be familiar with these synonyms to avoid any confusion or misunderstandings in email communication.