Use Confidential Mode if you have to share sensitive information through Gmail

It’s a best practice not to send sensitive, personal information over email whenever possible. When it can’t be avoided, Confidential Mode can give you some peace of mind. Before you hit Send, from the bottom row of the toolbar, select the Confidential Mode icon. It looks like a clock face with a padlock. You can set an expiration for the message and require an SMS passcode.