This year in May, Google rolled out the Confidential Mode for Gmail users on desktop, however, the feature is now available on the iOS and Android mobile application as well. Gmail announced the same via a tweet on 16 August. The feature will "help you protect sensitive information from unauthorized access."
The new confidential mode can be used to set an expiration date for their emails or revoke access at any time. Recipients of the confidential message will have options to forward, copy, print, download and forward disabled. They will also need a passcode to access the email.
Confidential mode is now available on mobile devices and can help you protect sensitive information from unauthorized access. Learn more about this feature → https://t.co/lmQNElH6C1 pic.twitter.com/Nxtx2yU0pG
— Gmail (@gmail) August 16, 2018
The confidential mode isn't available in classic Gmail though. You have to enable it.
To do so, on your computer or mobile phone, go to Gmail and click compose. In the bottom right of the window, click 'Turn on confidential mode.' You can now set an expiration date and passcode. These settings will apply to both the message text and any attachments in the email.
Further, if you choose "No SMS passcode," recipients using the Gmail app will be able to open it directly. Recipients who don't use Gmail will get passcode via an email. If you choose "SMS passcode," recipients will get a passcode by text message. Make sure you enter the recipient's phone number, not your own.
Click Save and then you're good to go.