End-to-end email encryption is a method of transmitting data where only the sender and receiver can read email messages. With end-to-end email encryption, the data is encrypted on the sender’s system. Only the intended recipient will be able to decrypt and read it. Nobody in between can read the message or tamper with it. End-to-end email encryption provides the highest level of confidentiality and protection to your email communication. Most popular Email services do use a level of encryption, mostly SSL/TLS. For example, when you visit a site like https://www.gmail.com, the HTTPS in front of the URL denotes that SSL/TLS protocol has been used to encrypt the data transferred between your computer and the Gmail servers. This protocol is much more secure than HTTP (without “S” = not secure). Most websites adopted SSL/TLS to protect against malicious intermediaries. The downside to relying solely on HTTPS, is that data is only encrypted between your device and the Gmail servers. Gmail has the keys to decrypt that data. The following Email services do offer complete end-to-end encryption. Of course there are many other services that offer the same and we will keep this list updated to reflect the same. Also it is worth noting that while some of these services are free, most of them operate on a Freemium basis meaning there is a free option with limited features and functionality and a paid version that unlocks the full potential of the service.
ProtonMail
Developed by CERN and MIT scientists and protected by Swiss privacy law, this one rose to fame for this very reason. ProtonMail is the world’s largest secure email service. They offer a free version of their service with limitations like 500MB storage, 150 messages per day and Limited Support though upgrading to their Plus package ups these to 5 GB storage, Send up to 1000 messages per day, Labels, Custom Filters, and Folders, Send encrypted messages to external recipients, Use your own domain (ex: [email protected]) Up to 5 email aliases and Priority Customer Support
Microsoft Outlook
Outlook rolled out end-to-end encryption to protect business email back in April of this year. Outlook also asks a user if they wish to encrypt an email if it detects sensitive information, like a bank account number, in the email. The new Outlook will give users options for how secure you’d like your emails to be. There are also features that would block people receiving your emails from being able to forward or copy the message.
Tutanota
Tutanota prides itself in being the Encrypted Open Source Email Service for Privacy Minded People. Tutanota is a German based, privacy centered email provider. These guys refer to their product as “Secure mail for everyone.” unlike ProtonMail, Tutanota does not advertise its location as a feature of the service, and instead puts their marketing emphasis on encryption and ease of use. Tutanota has multiple ways that it has implemented encryption. It has end-to-end encryption between Tutanota clients, as well as optional password protected encryption when a Tutanota user is emailing someone using another email provider. How this works is if I, a Tutanota user, wants to send an encrypted email to my coworker, a Gmail user, for example, we can agree on a predetermined password that will allow us, and only us, to see the email.
Mailfence
Mailfence is based in Belgium and is subject to EU and Belgian laws and regulations. What you get with mailfence is an email address and web service that incorporates OpenPGP public key encryption like any email program would. You can create a key pair for your account and manage a store of keys for people you want to email securely. That concentration on the OpenPGP standard means you can access Mailfence using IMAP and SMTP using secured SSL/TLS connections with the email program of your choice. It also means you cannot use Mailfence to send encrypted messages to people who do not use OpenPGP and have no public key available.
Hushmail
Hushmail is one of the few that touts its security above all of its features. While Hushmail is a secure solution for email communications, the free side of the service lacks many of the features and functionality that make other web-based email clients so appealing while being just as secure as Hushmail. As part of its security features, Hushmail scans incoming email for viruses, and the service is equipped with a spam filter, as is standard for free email services. This service also gives you the basic function to create blacklists and whitelists to secure your email inbox even more. This means that you can tell the service which senders you trust and which domains you do not wish to receive email from. You can block domain names as well as individual email addresses. This is also commonplace for basic email accounts.
