When you prepare the message in Gmail, you can set it as confidential if you do not want the recipients to share the message. The recipient will not have the option to forward, copy, print, or download the email.
Step 1: To first compose an email by clicking the "Compose" button on the top-left corner;
Step 2: Finish the "To" box and the "Subject" box, then finish the email;
Step 3: Before clicking the "Send" button, click the "Confidence" icon at the bottom of the message;
Step 4: In the new window, select the expire date then decide whether you need a password;
Step 5: Click the "SAVE" button and you will see the note at the bottom of the message;
Step 6: If you are the recipient, you will see the same note when you open the message.