
Description: Isotope Mail Client is an open-source, privacy-focused email client for Windows, macOS and Linux. It supports end-to-end encryption using PGP and aims to provide a simple, easy-to-use interface while still allowing advanced configuration options.
Type: Open Source Test Automation Framework
Founded: 2011
Primary Use: Mobile app testing automation
Supported Platforms: iOS, Android, Windows

Description: Squirrelmail is an open source webmail client that allows users to access email accounts through a web browser. It supports SMTP, POP3 and IMAP protocols for sending and receiving emails.
Type: Cloud-based Test Automation Platform
Founded: 2015
Primary Use: Web, mobile, and API testing
Supported Platforms: Web, iOS, Android, API