The Internet's "killer app" is not the World Wide Web or Push technologies: it is humble electronic mail. More people use email than any other Internet application. As the number of email users swells, and as email takes on an ever greater role in personal and business communication, Internet mail protocols have become not just an enabling technology for messaging, but a programming interface on top of which core applications are built. Programming Internet Email unmasks the Internet Mail System and shows how a loose federation of connected networks have combined to form the world's largest and most heavily trafficked message system. Programming Internet Email tames the Internet's most popular messaging service. For programmers building applications on top of email capabilities, and power users trying to get under the hood of their own email systems, Programming Internet Email stands out as an essential guide and reference book. In typical O'Reilly fashion, Programming Internet Email covers the topic with nineteen tightly written chapters and five useful appendixes. Following a thorough introduction to the Internet Mail System, the book is divided into five parts: Part I covers email formats, from basic text messages to the guts of MIME. Secure email message formats (OpenPGP and S/MIME), mailbox formats and other commonly used formats are detailed in this reference section. Part II describes Internet email protocols: SMTP and ESMTP, POP3 and IMAP4. Each protocol is covered in detail to expose the Internet Mail System's inner workings. Part III provides a solid API reference for programmers working in Perl and Java. Class references are given for commonly used Perl modules that relate to email and the Java Mail API. Part IV provides clear and concise examples of how to incorporate email capabilities into your applications. Examples are given in both Perl and Java. Part V covers the future of email on the Internet. Means and methods for controlling spam email and newly proposed Internet mail protocols are discussed. Appendixes to Programming Internet Email provide a host of explanatory information and useful references for the programmer and avid user alike, including a comprehensive list of Internet RFCs relating to email, MIME types and a list of email related URLs. Programming Internet Email will answer all of your questions about mail and extend your abilities into this most popular messaging frontier.