How to Encrypt an Email in Gmail: Gmail Confidential Mode vs Proton Mail

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Use Proton Mail for real end-to-end encryption; use Gmail Confidential Mode only for light message controls. Gmail’s option is handy, but it is not the locked steel vault many people think it is. Proton Mail is closer to that vault, with fewer “wait, why is this still visible?” moments.

TLDR: Gmail Confidential Mode lets you set an expiry date, add a passcode, and stop easy forwarding or downloading. It does not give you true end-to-end encryption. Proton Mail does, especially when you email another Proton user. Example: if a freelancer sends 12 invoices a month with bank details, Proton Mail is the safer pick, while Gmail Confidential Mode is fine for a quick file review link that expires in 7 days.

First, what does “encrypt an email” mean?

Encryption means your message is scrambled so only the right person can read it.

Think of it like sending a locked lunchbox. The email provider may carry the lunchbox. The internet may toss it around. But only the recipient should have the key.

There are a few levels here:

  • TLS encryption: Protects the trip between mail servers. Most major email services use it.
  • Access controls: Stops some actions, like forwarding or downloading. This is what Gmail Confidential Mode mostly does.
  • End-to-end encryption: Only sender and recipient can read the message. This is what Proton Mail focuses on.

That difference matters. A lot.

How to use Gmail Confidential Mode

Gmail makes this pretty easy. Nice for once.

  1. Open Gmail.
  2. Click Compose.
  3. Write your email.
  4. At the bottom of the compose window, click the lock and clock icon.
  5. Pick an expiration date. Options include 1 day, 1 week, 1 month, 3 months, or 5 years.
  6. Choose whether to require an SMS passcode.
  7. Click Save.
  8. Send the email.

If you choose SMS passcode, Gmail may ask for the recipient’s phone number. The recipient gets a code by text. They need that code to open the message.

This feels secure. And in some ways, it is better than a normal email. But the label can be a little generous.

What Gmail Confidential Mode actually protects

Gmail Confidential Mode can help with simple control.

  • You can set the message to expire.
  • You can remove access later.
  • The recipient cannot easily forward, copy, print, or download it from Gmail’s interface.
  • You can add SMS verification.

That is useful. If you send a draft contract, a private note, or a temporary login detail, it can reduce casual mistakes.

But here is the annoying part. The recipient can still take a screenshot. They can photograph the screen. Malware could capture it. A determined person can still copy the information by hand. So no, this is not magic.

Also, Gmail Confidential Mode is not the same as true end-to-end encryption. Google’s systems still handle the message. That may be fine for normal use. It may not be fine for legal, medical, financial, or whistleblower-style communication.

Can Gmail send real encrypted email?

Yes, but not in the simple free-Gmail way most people want.

Some Google Workspace plans support S/MIME. This can encrypt emails between users who have the right certificates set up. Larger organizations may also use client-side encryption in certain Google Workspace editions.

Sounds good, right? Then the setup arrives. Certificates. Admin settings. Key handling. Recipient compatibility. Honestly, it feels like a 10-minute task that invited a committee.

For a regular Gmail user, Confidential Mode is the main built-in option. It is easy. It is not true end-to-end encryption.

How Proton Mail encryption works

Proton Mail is built around privacy from the start.

When you email another Proton Mail user, the message is end-to-end encrypted automatically. You do not need to click a special button. You do not need to become a part-time cryptography goblin.

Your message is encrypted before it leaves your device. The recipient decrypts it when they open it. Proton cannot read the message content in the same way a normal email provider can.

That is the big win.

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How to send an encrypted email with Proton Mail

If the recipient uses Proton Mail, it is simple:

  1. Open Proton Mail.
  2. Click New message.
  3. Write your email.
  4. Send it to another Proton Mail address.

That is it. The encryption happens in the background.

If the recipient does not use Proton Mail, you can still send a protected message:

  1. Compose your email in Proton Mail.
  2. Click the lock icon.
  3. Set a password.
  4. Add an optional password hint.
  5. Send the message.
  6. Share the password through another channel, like a call or secure chat.

The recipient gets a link. They open it, enter the password, and read the message in a secure web page.

Do not send the password in the same email. That is like taping the key to the locked door.

Gmail Confidential Mode vs Proton Mail

Here is the simple version.

Feature Gmail Confidential Mode Proton Mail
True end-to-end encryption No, not for regular Gmail users Yes, especially Proton to Proton
Expiration dates Yes Yes, for password-protected messages
Passcode option Yes, by SMS Yes, with a shared password
Stops screenshots No No
Best for Quick access control Private communication

When Gmail Confidential Mode is enough

Use Gmail Confidential Mode when the risk is low or medium.

  • You are sending a short note that should expire.
  • You want to stop accidental forwarding.
  • You are sharing a draft with a coworker.
  • You need a simple SMS check.
  • You already live in Gmail and need speed.

It is good for everyday privacy. It is not built for secrets that could cause real damage if exposed.

Expect to waste a few extra seconds setting the expiry and SMS option. Not awful. Just slightly clunky when you are sending several messages in a row.

When Proton Mail is the better choice

Use Proton Mail when the content is sensitive.

  • Medical details.
  • Legal documents.
  • Tax files.
  • Bank information.
  • Private business plans.
  • Personal messages you truly want kept private.

Proton Mail is also better if you often email the same privacy-minded people. Once both sides use Proton, encrypted email becomes boring. Boring is great. Boring means you do not have to think about it.

What about attachments?

Attachments deserve extra care.

In Gmail Confidential Mode, recipients cannot download attachments in the usual way if the message is protected. But again, this is access control, not full end-to-end encryption.

In Proton Mail, attachments are encrypted with the message when sent to another Proton user. For outside recipients, password-protected messages can secure the content behind a link.

If you must use Gmail for a sensitive file, consider encrypting the file first. For example, use a password-protected ZIP file with strong encryption. Then share the password by phone or another trusted channel. It is less smooth, but safer.

Quick safety tips

  • Use a strong password. “Summer2024” is not strong. Sorry.
  • Turn on two-factor authentication. Do this for Gmail and Proton Mail.
  • Check the recipient address. Autocomplete can betray you.
  • Do not send passwords in the same email. Ever.
  • Assume screenshots are possible. Because they are.

The simple verdict

Gmail Confidential Mode is a privacy speed bump. It slows down casual sharing. It adds expiry dates and passcodes. It is useful.

Proton Mail is a stronger privacy tool. It gives you real end-to-end encryption when used correctly. It is better for sensitive messages.

If you only need a message to expire, Gmail is fine. If you need the message to stay private from email providers, servers, and snoops, use Proton Mail. Your future self will thank you.