Note: Before you can do this read receipts must be enabled on your domain by your Google Apps Administrator for you to access this feature.
Here’s how to request a read receipt:
- Compose (or Reply to) a message as usual in Gmail
- Click the More options icon in the lower-right corner of the compose window
- Click Request read receipt from the drop down
- Send your message
Receipt requests will be sent to every recipient in the To: and Cc: fields. It does not send a request to recipients in the Bcc: field.