1 \clearpage

2 \chapter*{Preface}

3 \addcontentsline{toc}{section}{Preface}

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5 This thesis is about \masqmail, a small mail transfer agent for workstations and home networks. In October 2007 I chose \masqmail\ for my machines because it is a small though ``real'' mail transfer agent. \masqmail\ served me well since then and I found no reasons to change.

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7 Unfortunately, the \masqmail\ package in \debian, which is my preferred \NAME{GNU}/Linux distribution, is unmaintained since the beginning of 2008. Unmaintained packages are likely to get dropped out of a distribution if critical bugs appear in them. Although \masqmail\ had no critical bugs, this was a situation I definitely wanted to prevent.

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9 Using my diploma thesis as a ``power-start'' for maintaining and developing \masqmail\ in the future was a great idea. As it came to my mind I knew this is the thing I \emph{wanted} to do. --- I did it! :-)

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11 \quad

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13 The overall goal of this document is to revive \masqmail\ in usage and development. \masqmail\ was not developed in the last five years although the world of email changed during this time. Hence quite some work needed to be done.

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15 I chose to start down at the basis and analyze the environment and \masqmail\ throughout to end in concrete plans of what should be done and how it should be done to turn \masqmail\ into a modern mail transfer agent again.

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17 The actual implementation of the the proposed changes goes beyond this thesis. Here are solutions identified, described, discussed, and recommended but not implemented. I did work in the code and have fixed bugs during the time I wrote on the thesis, though.

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19 \quad

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21 This document is primary written with an audience of \masqmail\ developers and developers of other mail transfer agents in mind. But users of \masqmail\ and everyone who is interested in email systems in general may find this thesis an interesting literature.

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23 However, at least basic knowledge about \unix\ and C programming is preconditioned in chapter three, four, and five. \person{Kernighan} and \person{Pike}'s ``The \NAME{UNIX} Programming Environment'' \cite{kernighan84} is a valuable source to gain information about \unix. Programming in the C language is best learned from \person{Kernighan} and \person{Ritchie}'s ``The C Programming Language'' \cite{k&r}.

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32 \section*{Organization}

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34 Six chapters structure this document. Each one covers a delimited part of the overall topic and builds upon the knowledge and results of the previous ones. The first three chapters lead into the topic and create a solid base where the second part builds upon. Chapter four and five are the central part of the thesis as they focus on \masqmail.

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36 Chapter 1 \textbf{introduces} \masqmail\ to the reader. It presents the properties, goals, advantages, and problems of the program. Basic concepts of the email technology are also described and later assumed to be know.

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38 Chapter 2 \textbf{analyzes the market} of electronic communication and email. This chapter shows that email will remain an important technology in the future which is a precondition for investing effort into it. It tries to identify future trends too.

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40 Chapter 3 \textbf{deals with mail transfer agents} (\MTA{}s) which are the most important entities of the email transport structure. \MTA{}s are defined, classified, and important ones are presented and compared.

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42 Chapter 4 \textbf{focuses on \masqmail's present and future}. It is the core of the thesis. Requirements are identified and lead to a list of pending work tasks. Then possible strategies for future development are discussed.

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44 Chapter 5 \textbf{describes improvement plans}, which are based on decisions in chapter four, in more detail. A proposed architecture for a redesigned \masqmail\ is presented too.

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46 Chapter 6 \textbf{summarizes} the most important results and closes the thesis.

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53 \section*{Conventions}

54 %TODO: check it!

55 The following typographic conventions are used in this thesis:

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57 \begin{enumerate}

58 \item \emph{Italic shape} is used to emphasize text, to introduce new terms, and for names, including product, host, and user names, as well as email addresses.

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60 \item For names of persons \textsc{Small Caps} are used.

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62 \item File and path names, contents of files, and output from programs are displayed in \texttt{Typewriter font}.

63 \end{enumerate}

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65 References to external resources are marked using one of three styles, distinguished by the type of resource.

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67 \begin{enumerate}

68 \item References to books, articles, and similar documents looks like this: \cite{kernighan84}. The letters represent the author(s) (here \person{Kernighan} and \person{Pike}), the number represents the year of publication (here 1984).

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70 \item Websites differ from documents as they are less of a text written by some author but more a place where information is gathered. They are only indicated by numbers, like for example: \citeweb{masqmail:homepage}.

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72 \item \name{Request for Comments}---the documents that define the Internet---are referenced in a third way, by specifying the unique number of the \RFC\ directly: \RFC\,821.

73 \end{enumerate}

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75 The Bibliography is located at the end of the thesis. It also includes a list of the relevant \RFC{}s and how they can be retrieved.

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81 \section*{Acknowledgments}

82 %FIXME: write this at the very end.

83 % dont forget: proove readers, suggestion makers, supporters, ...

84 %\input{/home/meillo/da-various/acknowledgments.tex}

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89 \vspace{9ex}

90 { \it

91 \hspace*{23em}markus schnalke\\

92 \hspace*{23em}February 2009

93 }