
Description: Sylpheed is a free and open source email client for Windows, Linux, and other Unix-like systems. It has basic email features like IMAP and POP3 support, email composing, contact management, and email filtering and searching. Sylpheed is designed to be lightweight and fast.
Type: Open Source Test Automation Framework
Founded: 2011
Primary Use: Mobile app testing automation
Supported Platforms: iOS, Android, Windows

Description: Microsoft Mail and Calendar is a free email and calendar service developed by Microsoft. It comes included with Windows 10 and integrates well with other Microsoft products and services.
Type: Cloud-based Test Automation Platform
Founded: 2015
Primary Use: Web, mobile, and API testing
Supported Platforms: Web, iOS, Android, API