Google uses TLS (so-called standard encryption) to keep the emails you send relatively safe. Please note that this service also has S.MIME encryption which is more secure, but it is only available for business and educational institutions.
However, there are other ways to keep users' private data a little more secure, and one of them is to use confidential mode.
Google introduced confidential mode for Gmail in 2018. This setting allows people to send messages that can expire and prevents recipients from copying their content, forwarding them to others, or downloading them.
You can use confidential mode on your desktop or through the Gmail app on your mobile device. No matter what device you're using, you must enable confidential mode every time you send a message.
Using web browser
1. Write a new message
2. Look for the ‘lock and time' icon to the right of the Send button, and press it.
3. A pop-up will appear allowing you to set the parameters for how long you want recipients to have access to your message before it expires (ranging from one day to five years).
4. Under the expiration date, you will see the Require Passcode category. If the person you're emailing has Gmail, and you want an extra layer of security, select an SMS passcode to also ask them to enter a passcode that will be sent via SMS to their phone number. If the recipient doesn't have Gmail, even if you select No SMS passcode, they will be emailed a passcode.
5. A notification that the message is being sent in confidential mode will appear at the bottom of the message.
Using a mobile device
These steps are mostly the same, but some items are in a different place than what you'd find in the browser. The process is the same for both iOS and Android versions of Gmail.
1. Write a message
2. Tap the three vertical dots in the top right corner of the app, then tap Confidential mode.
3. As with the browser, you will have the option to set how long the message is visible to the recipient and whether it is password protected.
4. After you adjust the settings, messages sent in confidential mode will display a small window at the bottom detailing how long the message will last before it expires.