RainLoop is an open-source, simple, modern, and fast Webmail client based on PHP. Some essential features include: * Intuitive, modern web interface that allows for custom theme uploads. * Complete support of IMAP and SMTP protocols, including SSL and STARTTLS. * Integration with Facebook, Google, Twitter, and Dropbox. * Built-in configurable multi-level caching system to improve performance. * Simultaneous access to different mail server accounts, for example, Gmail, Yahoo, and many more. * Sup......