This could allow the third party to perform analysis of the content of the email. The content of emails sent to third party email platforms will be visible to those third parties, unless you use the encryption feature. Any email you send to third parties is tied to your account and can be traced back to it as your sender address will always be visible.

Thus, if you include sensitive or identifying information in the subject line, this could be visible to third parties. This is because no email standard, even the PGP encryption standard supports encrypting this data. Subject lines of emails, as well as the recipient and sender addresses, are not encrypted during transmission.

This could potentially be used to identify you, or at least where you live. What can be tracedĪs part of their service, ProtonMail does temporarily log some metadata such as IP addresses. You should be aware that a lot of governments actively try to track activity on the tor network, meaning it may in some cases draw more attention to you than just accessing the site normally. ProtonMail offers a hidden tor site, also known as an onion site, that can be accessed over the tor network for connection and IP address anonymity. This means that ProtonMail can’t access or analyse your emails at all, or hand over that data. Messages between ProtonMail accounts are encrypted from end to end and all emails are encrypted when stored on ProtonMail’s servers. You should make sure that your email address doesn’t include any identifying information and that you don’t reuse the handle of another email address with ProtonMail as this could be used to link the two accounts. This anonymity only goes so far though, if you want true privacy you should practice proper OPSEC, or Operational Security. ProtonMail doesn’t require any personal details to sign up, so your account is essentially anonymous. Details of the cases that they did and did not provide information for can be found in their transparency report. While this does happen occasionally, ProtonMail also pushes back on many cases that they object to. ProtonMail cannot legally comply with a court order from a foreign government unless the Swiss government approves it. As ProtonMail is based in Switzerland it is subject to Swiss laws that are well known to be very pro-privacy.

Proton email service