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...