A delivery receipt tells you that an email message was delivered to the recipient’s mailbox, but not whether the recipient has seen it or read it. A read receipt tells you that a message was opened. In both cases, you receive a message notification in your Inbox.
The recipient may decline to send a read receipt. In addition, the recipient’s email program might not support read receipts.
In the open message, on the [Options] tab, in the [Tracking] group, select the [Request a delivery receipt] or the [Request a read receipt check box].
Note*** Receipts are recorded in the original message in Sent Items. Open the message, and then on the Message tab in the Show group, click Tracking.