Proton Mail-Zero access?---SOLVED

I’ve been trying to get a rock solid answer to this question about Proton Mail.
I know it is end-to-end encrypted but is it zero access?
I know subject lines are not encrypted in-transit but the body is encrypted.
Can Proton view emails if they choose to, or have they ensured that they do not have that capability?
I have been told by a reliable source that Proton’s encryption is transport only, and even though they appear to never have done so, Proton could view anyone’s emails if they were forced to do so by a legal order.

[This has been solved. Proton contacted me with the answer.

  • End-to-End Encryption and Zero-Access are two different things. End-to-End Encryption is for transport and is automatic between Proton users and can be applied from Proton users to non-Proton accounts by using the password protected email options (the little padlock).
    -Zero-access applies to storage. All emails, including drafts are encrypted at rest and Proton cannot access them even if they wanted to.
    -Incoming emails from non-Proton sources are accessible to Proton and could be read if Proton wanted to, or if they were forced to by a court order. To mitigate this risk, Proton encrypts incoming non-Proton emails on arrival and places them in your in-box. At this point they become Zero-Access and Proton can no longer view them. The problem here is that if there is a court order to collect incoming emails from a non-Proton source then these emails can be copied and stored before they are encrypted and sent to your in-box.]

Most emails are not end-to-end encrypted.

When Proton receives an unencrypted e-mail they encrypt it with your public key, after this point you are the only person who can decrypt the message. Proton can’t decrypt your emails, if a warrant is issued they can intercept all unencrypted emails sent to your e-mail address, but even with a warrant they can’t read your end-to-end encrypted emails.

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If I understand that correctly, then all the mail in my inbox, whether it came from another Proton account or not, is encrypted.
How about the drafts? They haven’t been sent or received, so I assume they haven’t been encrypted.

Your drafts are encrypted.

Everything you create is stored with zero access encryption, it’s encrypted by the client and the server never has access to the unencrypted message.

Keep in mind that some data fields are not encrypted, and you should assume only the body is encrypted.

Data created by others is not end-to-end encrypted unless they encrypt it with your public key before sending it to you, which is why the server can see the message. Proton does the best they can by encrypting the message for you, but until the message is encrypted, they have access to the unencrypted message.


Which is correct?


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It’s TLS encrypted, it’s not PGP encrypted.

Figured I’d add in what I know here, as I had similar questions not too long ago. Here’s is what I learned with my conversations with support. Do note, this is strictly for the Email service, and nothing else.

  1. Stored email contents is encrypted at rest, only unencrypted with your login details (PGP key). If you loose those, you will not be able to read your emails.
  2. Stored email addresses, subject lines, folders, and tags, ARE NOT encrypted. These are readable by Proton, at any time. This is due to some Protonmail functionality (such as Search), and to allow account recovery (to prove who you are). I went through this process when I lost my 2FA device (that’s when I started backing that stuff up).
  3. All email sent to another Proton account is e2e encrypted, but zero-access to the contents.
  4. All email sent with an added Password uses an extra layer of TLS encryption, along with the usual PGP. TLS encryption can also work with sending emails to other providers (eg: Gmail), so long as the recipient knows the password you made. Even the recipient email provider would not be able to read contents.
  5. Emails sent to your Proton address, from another service (eg: Gmail) that are sent unencrypted. Proton can read everything within the email. They then encrypt the contents with your PGP key. Though, by the time they encrypt it, they could have already made an unencrypted copy… again, trust is key, here.
  6. Emails that are send encrypted (eg: with TLS), Proton cannot read. However, they would also encrypt it again, with your PGP. Proton would have zero access to the emails contents.

Note: anytime I mention email contents, I’m talking about the email body and attachments.

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Yes, it’s zero access.

Read more: How Safe is Proton Mail? Security Features Explained

Yeah sorry the wording were a bit ambiguous. I meant to say Protonmail Email headers are HTTPS/TLS 1.3 encrypted. But they can’t be e2ee due to the decentralized & badly designed email protocol.

If you send it to another proton user or another proton user sends it to you or when you use the password option in these casses it is zero acces otherwise it is the standard e2ee wich emails provide. And other secure providers like tutanota work the same way