An Apple Mail developer works on enhancing and maintaining Apple's native email application, Mail. Their responsibilities include writing and debugging code, implementing new features, and ensuring the app is user-friendly. They work on improving the app's speed, efficiency, and security while maintaining compatibility with various email protocols and services. They collaborate with UI/UX designers for design implementation and with QA teams for testing. Developers also need to stay updated with new iOS updates and technologies, ensuring the Mail app remains compatible and optimized. They may also address customer feedback and issues, contributing to a seamless user experience.