Even if it was enabled, it wouldn't really be reliable as it depends on the email/server configuration of the person you're emailing. These days email services and clients include the ability to block read receipts.
Even if it was enabled, it wouldn't really be reliable as it depends on the email/server configuration of the person you're emailing. These days email services and clients include the ability to block read receipts.
Even at work the person can decline sending a receipt. I still get a few when using Outlook. At least a delivery message can still be obtained (though it doesn't prove the person read the email it does show it was successfully delivered).