Gmail confidential mode is a feature that allows users to send messages and attachments with certain controls to help protect sensitive information from unauthorized access. When a message is sent in confidential mode, Gmail replaces the message body and attachments with a link. Only the subject and link are sent, using SMTP. The recipient of the confidential message will have options to forward, copy, print, and download disabled. Users can set an expiration date for messages or revoke access at any time. However, it is important to note that confidential mode cannot prevent recipients from taking screenshots or photos of the messages or attachments, and recipients who have malicious programs on their computer may still be able to copy or download the messages or attachments. Confidential mode is not a substitute for actual encryption, but it is much easier to use than the encryption options found in other email clients. To use confidential mode, users need a Gmail account on either the web-based Gmail client or the mobile app.