There is a voluntary receipt system, it's called read receipts: https://support.google.com/mail/answer/9413651?hl=en https://support.google.com/mail/answer/941

There is a voluntary receipt system, it's called read receipts: https://support.google.com/mail/answer/9413651?hl=en https://support.google.com/mail/answer/9413651?hl=en https://support.microsoft.com/en-us/office/add-and-request-read-receipts-and-delivery-notifications-a34bf70a-4c2c-4461-b2a1-12e4a7a92141 https://support.microsoft.com/en-us/office/add-and-request-r...