Learn how Gmail encrypts your emails

Transport Layer Security (TLS): Standard protection for your emails

Available for: All Gmail accounts

All Gmail messages use TLS automatically. Think of TLS as a secure mail carrier for your messages.

• When you send a message in Gmail, it’s like you give a letter to a reliable mail carrier.
• If the recipient also uses this secure mail carrier, your message is protected.

Almost all major email services use TLS. When you send or receive a message in Gmail, your message is protected and marked with a gray lock icon , also known as standard encryption.

Secure/Multipurpose Internet Mail Extensions (S/MIME): Extra protection for sensitive emails

Available for: Work or school Gmail accounts

For a higher level of security, Gmail supports S/MIME. Imagine S/MIME as a locked briefcase and only you and your recipient have the keys so that:

• When you send a message, you put it inside the briefcase and lock it with a unique key.
• The secure mail carrier (S/MIME) transports the briefcase and can’t open it.
• Only the recipient can open the briefcase with their matching key.
• Even if someone intercepts the briefcase, they can’t open it without your key.

There are 2 key-management options for S/MIME:

• Hosted S/MIME: Google securely manages a copy of your key. These messages are marked with a green lock icon , also known as enhanced encryption. Learn about hosted S/MIME.
• Client-side encryption (CSE): Your organization holds the only copy of the key. Not even Google can open your briefcase. These messages are marked with a blue shield icon , also known as additional encryption. Learn about Gmail CSE.

Learn how to verify email security

There are two ways to verify email security:

• On your computer or Android device, when you compose a message, select Message security .
• When you receive a message, open the recipient details.
• If you get a message with a red open lock icon , it means the message is unencrypted. You should:
  • Not send sensitive information.
  • Let the sender know their message is unencrypted.

Learn how to check your email security.