You can request a read receipt for messages you send to help verify that a recipient has indeed opened the email. When the recipient looks at your message, they will be prompted to answer the request. Once they answer the request, a message will be sent to you letting you know that they opened the email.
1. Click the New Mail button from the toolbar.
2. Address and compose your message.
3. Go to the menu, click Message and select Request Read Receipt.
4. Send the message.
