Cryptext is an encrypted email service built upon Signal protocol. It guarantees security, privacy, and control over user accounts with end to end encryption which means that only you and your recipient has the access to the content of your messages.
Cryptext does not store any messages in the cloud or in their servers, all messages are stored on the user's devices instead.
Cryptext is free to use and can be downloaded for iPhone, Android, Mac, Windows, Linux and has support for multiple email accounts.