What a shit show: "When someone sends a confidential mode message, Gmail removes the message body and any attachments from the recipient's copy of the message.

What a shit show: "When someone sends a confidential mode message, Gmail removes the message body and any attachments from the recipient's copy of the message. These are replaced with a link to the content. Gmail clients make the linked content appear as if it's part of the message. Third-party mail clients display a link in place of the content." So it's neither confidential (google can read it), nor an email (as it's just an email containing a link to some google site).