The only purpose of DSN "Delivery Status Notification" receipts is to let a sender know when the recipient's '''server''' received the message. Note: that many servers are ignoring DSN requests partly as a measure to not auto respond to what may be spam. "Return Receipt" when composing a message it will add the "Disposition-Notification-To: ..." header to the message that requests the recipients email client to send a reply and specifies who to send the reply to. However, you can't rely upon this because many email clients and webmail let the recipient decide whether to ignore return receipts, or to decide on a case by case basis whether to allow the return receipt. So the recipient might respond or might ignore the request. Some servers may even remove the "Disposition-Notification-To: ..." header to remove the choice entirely so their users do not even see a 'Return Receipt' request. Sending Return Receipt will add additional load on their number of sent mail quotas. So, whilst you can request DSN and/or Return Receipt, you cannot be guaranteed a reponse.