How to know if my message has been read? Outlook

Thank you for your prompt response (I apologize for my late reply).

I followed this procedure, but how will I be notified now? Because next to the email sent yesterday, I don't see anything specific that resembles an envelope indicating receipt or something similar.
I also sent an email to myself on a second email address and opened it yesterday to make sure I read it and compare the two.
I'm not sure if I'm being clear in this response, but basically I would like to know what indicates receipt. Is it through an icon? Or something else?

Thank you.

(yes I changed accounts) If the recipient has pressed the button indicating that they have confirmed receipt, you will receive an email informing you that "such-and-such" has received your message: for example, I received: "This is a confirmation of receipt for the email sent to xxxxxxxxxx@laposte.net.

Note: This confirmation of receipt indicates only that the message has been displayed on the recipient's computer. There is no guarantee that the recipient has read or understood the content of the message."

Here is the standard message you could receive.