Welcome to Internet Messaging. This is a book about how you can use e-mail on your desktop, in your enterprise and throughout the Internet.

Internet messaging provides a rich and widespread infrastructure for collaboration. It offers a variety of services-from personal messaging to distribution lists to exotic mail-based applications, and from simple textual memos to complex multimedia objects. It operates under a variety of circumstances and connection speeds, from computers using dedicated high-speed links or local area networks to roaming users of dialup lines. The Internet messaging infrastructure is widespread because it connects the commercial, government, research and education sectors in every continent on the globe. Despite the tremendous differences in end-user equipment, messaging formats and the like, it all manages to work together.

There's a lot of technology that goes into making the Internet messaging infrastructure a success. The objective of this book is to present it to you in a fashion that is understandable and accurate. Let's not confuse accuracy and detail; it's important that we provide you with information that is correct. But it's just as important that we don't allow technical nuances to obscure the larger picture. So, we've taken care that we emphasize the fundamentals. Similarly, because this is a practical book, we focus on those issues that may affect you in your daily life or your strategic planning. In essence: We talk about standards, but only as a means to an ends; and we don't talk about bits and bytes, unless they serve some larger relevance to you as a user.

Our strategy in organizing this book is simple. We started with 12 problems that appear to be rather consistent throughout the user community. We organized the 12 problems into six categories and developed a taxonomy to relate the categories. Each category was written as a chapter. We hope this provides an effective way for you to approach the information we're presenting. Since we've cross-referenced related issues in each chapter, the organization of this book allows you a fair amount of random access (read: "flipping") between chapters. So, after you've read the first chapter that introduces the taxonomy and categories, you can skip to different chapters based on your concerns of the moment.

In the interests of full disclosure, you should know our background and experience.

David Strom has used more than 15 different e-mail products for about a dozen different employers over 18 years of work. These products span a wide range, from the early IBM-host based DISOSS and PROFS systems and character-based MCIMail and AT&T Easylink, to LAN-based products such as cc:Mail and 3+OpenMail, to more recent Internet-based products. He runs his own consulting practice and has been using Eudora on both Macintosh and now Windows95 for the past several years as his principal e-mail product, although he has been known to occasionally run Pine and Netscape Messenger.

Strom's background is in technical product research and testing-he has tested hundreds of computer products, including Internet software, network operating systems, PC systems and communication applications. He advises computer vendors on product design and strategy. In the past decade, he has written close to 1,000 articles for various computer trade magazines on a wide variety of networking and communications topics. Before becoming a consultant, he founded CMP Media's Network Computing magazine and hired its first staff of editors. He has also run new product research for Transamerica Occidental Life Insurance and worked as an analyst and in-house consultant in information-center and end-user computing departments.

Marshall Rose has participated in the design and implementation of half a dozen e-mail products-and he is a heavy user of them. These products span a wide range, from the ground-breaking MH system (starting with the 1981 edition, which still has useful features not found in "modern" products), to the Safe-Tcl package used to write mail-enabled applications (such as exploders and spam filters), to First Virtual's Internet Payment Systems (the first Internet-based payment system, which, coincidentally, made heavy use of e-mail). In parallel, he also uses e-mail packages on both the Macintosh and Windows systems, although he currently favors Outlook Express on Windows95.

Rose's background is in Internet technologies. He's authored more than 60 Internet Requests for Comment (RFCs), implemented most of them, and productized or provisioned many of them. Although the majority of his work is in e-mail, he's also worked in directory services and network management. He also runs his own consulting business, but spends most of his time at First Virtual, where he leads a group developing interactive, reactive and transactive advertising technologies that are just as at home in e-mail as on the Web.

There have been several reviewers who spent considerable time correcting our draft manuscript, including Bill Frezza, Steve Birgfeld, Gary Gunnerson and Thomas Powell. Copy editing was expertly provided by Michael Perreca.

Marshall wrote this book in his spare time, as an employee of First Virtual Holdings Inc., the e-messaging company he cofounded back in 1994. Although a lot of First Virtual's technology is e-mail-based, there's nothing specific to First Virtual in this book, with the exception of some of the future applications described in Chapter 8.

Marshall learned to sail back in late 1996, despite being extraordinarily predisposed to motion sickness. (In fact, his physician prescribes medication to combat this malady.) In late 1997, Marshall bought a small auxiliary sloop (read: "a sailing vessel with a single mast and a tiny, interior diesel engine") that he named Azaka. He wrote most of his portions of the book while recommissioning the boat (although a small boat, it now carries more electronics and safety gear than most airplanes). The reason this is relevant is that he did most of the actual writing on his boat using a laptop and cable Internet connection. Although the Internet service provider is branded as @Home, in this instance it would be more accurate to refer to it as @Boat. Amusingly enough, Marshall wasn't the first boat owner in San Diego to have a cable Internet connection, but he probably placed in the first 25 of his kind.

Finally, Marshall thanks David for collaborating with him on this book. After having written seven books about Internet technologies, Marshall had begun to get tired of writing, but David convinced him that there was more to say. In addition, David did more than his fair share of the work!

David wrote this book in his spare time, too-although it never seemed like there was anything but time to write. Unlike Marshall who wrote most of his chapters in one place, David wrote in several cities, using a combination of his own machines as well as borrowed computers-since he has given up on using a laptop for the past year. This is his first book, and he isn't sure he wants to consider a second anytime soon. Nonetheless, having Marshall as a writing partner has been a thrill and an inspiration.

April 1998

San Diego, California, and Port Washington, New York