From holiday photos to our purchasing history to personal correspondences, our emails contain a great deal of sensitive information. It is therefore vital to keep your inbox and messages secure. This is more difficult than it first appears, as email was invented and widely adopted in the early days of the internet before many of today’s security best practises were developed. As with all digital content, the best way to keep emails secure is by using encryption — complex algorithms that prevent anyone from reading the content unless they have the correct encryption keys. In this article, we explain the different types of encryption that most email services use to protect your messages and what ProtonMail does to add an extra layer of security and privacy. How email is encrypted Most modern email services encrypt emails in two ways: They use TLS/SSL encryption in transit. This is the same encryption used to secure HTTPS websites, and it is