To send a read receipt in Outlook when someone opens an email that you've sent, please follow these steps:
- Open Microsoft Outlook on your computer.
- Click on the "File" menu in the top left corner of the screen.
- Click on "Options" in the left-hand menu.
- Click on "Mail" in the left-hand menu.
- Scroll down to the "Tracking" section and check the box next to "Delivery receipt confirming the message was delivered to the recipient's email server" and/or "Read receipt confirming the recipient viewed the message".
- Click "OK" to save the changes.
Note: Sending a read receipt depends on the recipient's email client and settings. Some email clients may not support read receipts, or the recipient may choose to decline the read receipt request.