
Description: SCRYPTmail is a free, open source email service focused on privacy and security. It uses client-side encryption to keep emails private, even from SCRYPTmail itself.
Type: Open Source Test Automation Framework
Founded: 2011
Primary Use: Mobile app testing automation
Supported Platforms: iOS, Android, Windows

Description: Sfletter is an open-source newsletter application that allows users to easily create, send, and manage email newsletters. It has a simple drag-and-drop editor for building newsletters and custom templates.
Type: Cloud-based Test Automation Platform
Founded: 2015
Primary Use: Web, mobile, and API testing
Supported Platforms: Web, iOS, Android, API