Worked on PHPMailer/PHPMailer to enhance both reliability and user experience by addressing OAuth2 token generation errors and expanding localization. Developed robust exception handling in PHP, ensuring that errors during OAuth2 token generation are surfaced to users with clear, actionable messages while preserving detailed diagnostics for developers. Improved error management by wrapping original exceptions, allowing for effective debugging without exposing sensitive details. Additionally, contributed Danish translations to the language files, broadening accessibility for Danish-speaking users. Focused on back end development, error handling, and localization, the work strengthened PHPMailer’s global reach and maintainability through thoughtful, user-centric engineering solutions.