Samsung has some own list of apps pre-installed in their devices. Samsung Email, is one of those which will come as a pre-installed one. It supports POP3, IMAP, and Exchange ActiveSync so that all your emails can be used in a single app.
Encryption is handled using S/MIME for secure email communication. Now the Samsung Email app has just passed 100 million downloads in Google Play store. Hope some of the Samsung users are using the app for their daily usage. Samsung Email app is added to the Play store in January 2017. App can be used only in samsung devices.