A MAPI (Messaging Application Programming Interface) developer specializes in creating and managing applications that use the Microsoft MAPI protocol for email functionality. They design email systems, calendars, and contact management systems by integrating MAPI with Microsoft Exchange Server and Outlook. They handle the sending, receiving, and storage of messages, and the management of attachments and folders. They also troubleshoot and resolve issues related to MAPI, ensuring smooth and efficient communication. Their work involves a strong understanding of Microsoft technologies, programming languages, and debugging tools. They often collaborate with other IT professionals to ensure seamless integration and functionality.