Proton Mail is the world’s largest encrypted email service. One of our most notable features is that we offer end-to-end encryption(new window) (E2EE) for emails. This means the sender encrypts an email on their own device, which can only be decrypted (opened) by its intended recipient on their device. No one else can read the email or open any files attached to it.
Emails sent between Proton Mail users are automatically end-to-end encrypted, but we also offer a feature called Password-protected Emails(new window). This allows anyone using another email service to receive emails from Proton Mail users with the same highly secure end-to-end encryption.
If you have received such an email, clicking on the link provided will take you to a secure Proton Mail environment where you can open it using a password or passphrase that the sender has shared with you by some other means.
This means only you (the intended recipient) can open the email and read its contents. Not Proton Mail, and not your own email service.
How to read and respond to an encrypted Proton Mail email
To open and read an email sent using Proton Mail’s Password-protected Emails feature:
1. Click the View Message button inside the notification email you have received. This will open a new tab in your browser to load a Proton Mail instance that ensures the contents of the email are secure.
2. Enter the password previously shared by the sender. Then click Decrypt.
3. The message will be decrypted on your device in your browser for you to read. No one else can read the message.
By default, all emails sent in this way automatically expire after 28 days, after which time they will no longer be available. The sender may have adjusted this time. When you open a message, the time left before it expires is clearly shown.
4. You can then Reply securely to the message. This reply is end-to-end encrypted. Full-text formatting options are available, and any attachments you send will also be end-to-end encrypted.
Because this is a free service, and to prevent abuse by spammers, you can only reply to each email a total of five times.
You can always create a free secure email account to enjoy the benefits of encrypted emails sent between Proton Mail accounts without reply limits or the need for message-specific passwords.
Is this safe?
Proton Mail uses open-source encryption algorithms to secure email communications with end-to-end encryption. This means the emails cannot be intercepted in transit or accessed by either Proton Mail or any other email provider. The only people who can read the messages are the sender and the recipient.
Proton Mail’s Password-Protected Emails are safe to open, and it is safe to click on View Message. You can verify the authenticity of the secure email by making sure you’re connected to the official Proton Mail website (and not a phishing site). The domain name should be proton.me.
Furthermore, you can check the secure email’s header information(new window) to make sure our DKIM and SPF records match what they should be. If you have any doubts, please contact our security team at firstname.lastname@example.org.