how do I request a read receipt in Apple Mail?

There is this: https://www.lifewire.com/request-read-receipts-os-x-mail-1172888

AFAIK, you would need to ask that of the recipient of the e-mail somewhere in the body of the e-mail.

if I found someone getting a "receipt" to see if the e-mail was read, that would be the last e-mail that user received from me. IMHO, that is a security risk.