Definition: PHPMailer v5.0.2 - A PHP email server client for sending, retrieving, and processing emails, originally designed by Scott Ballantyne at MailChimp. This version has improved compatibility with various mail clients and includes new features like HTML forms and custom styling. Detailed definition: PHPMailer is a PHP library that allows developers to easily send and receive e-mail messages using the MailChimp API. It's used to send, retrieve, and process email, making it suitable for developing applications or systems where you need to handle emails from various sources (like personal, work, etc.).