Webuzo SquirrelMail Stack is pre-bundled with all the dependencies and requirements like Apache, MySQL, PHP, etc. SquirrelMail is a standards-based webmail package written in PHP. It includes built-in pure PHP support for the IMAP and SMTP protocols, and all pages render in pure HTML 4.0 for maximum compatibility across browsers. SquirrelMail has all the functionality like email client, including strong MIME support, address books, and folder manipulation.