Mercurial > docs > diploma

comparison thesis/tex/1-Introduction.tex @ 78:3148ed044103

Find changesets by keywords (author, files, the commit message), revision number or hash, or revset expression.
wrote about structure and features of masqmail; quotation -> quote
author meillo@marmaro.de
date Thu, 06 Nov 2008 17:50:25 +0100
parents 6843dfd6c4fa
children 3b5ba7331eb5
comparison
equal deleted inserted replaced
77:a6d67c5f7d78 78:3148ed044103
36 36
37 The basic job of a \mta\ is to transfer/transport electronic mail from one host to another. 37 The basic job of a \mta\ is to transfer/transport electronic mail from one host to another.
38 38
39 Here are definitions from others: 39 Here are definitions from others:
40 40
41 \begin{quotation} 41 \begin{quote}
42 A mail transfer agent (MTA) is a highly specialized program that delivers mail and transports it between machines, like the post office. 42 A mail transfer agent (MTA) is a highly specialized program that delivers mail and transports it between machines, like the post office.
43 \cite{costales97} 43 \cite{costales97}
44 \end{quotation} 44 \end{quote}
45 45
46 \begin{quotation} 46 \begin{quote}
47 A mail transfer agent (MTA) (also called a mail transport agent, message transfer agent, or smtpd (short for SMTP daemon)), is a computer program or software agent that transfers electronic mail messages from one computer to another. 47 A mail transfer agent (MTA) (also called a mail transport agent, message transfer agent, or smtpd (short for SMTP daemon)), is a computer program or software agent that transfers electronic mail messages from one computer to another.
48 \citeweb{wikipedia:mta} 48 \citeweb{wikipedia:mta}
49 \end{quotation} 49 \end{quote}
50 50
51 \begin{quotation} 51 \begin{quote}
52 mail server (also known as a mail transfer agent or MTA, a mail transport agent, a mail router or an Internet mailer) is an application that receives incoming e-mail from local users (people within the same domain) and remote senders and forwards outgoing e-mail for delivery. 52 mail server (also known as a mail transfer agent or MTA, a mail transport agent, a mail router or an Internet mailer) is an application that receives incoming e-mail from local users (people within the same domain) and remote senders and forwards outgoing e-mail for delivery.
53 \citeweb{website:techtarget} 53 \citeweb{website:techtarget}
54 \end{quotation} 54 \end{quote}
55 55
56 \begin{quotation} 56 \begin{quote}
57 Message Transfer Agent - (MTA, Mail Transfer Agent): Any program responsible for delivering e-mail messages. Upon receiving a message from a Mail User Agent or another MTA, [...] it [...] delivers it to any local addressees and/or forwards it to other remote MTAs (routing) for delivery to remote recipients. 57 Message Transfer Agent - (MTA, Mail Transfer Agent): Any program responsible for delivering e-mail messages. Upon receiving a message from a Mail User Agent or another MTA, [...] it [...] delivers it to any local addressees and/or forwards it to other remote MTAs (routing) for delivery to remote recipients.
58 %Any program responsible for delivering e-mail messages. Upon receiving a message from a Mail User Agent or another MTA, often by SMTP over the Internet, it stores it temporarily locally and analyses the recipients and delivers it to any local addressees and/or forwards it to other remote MTAs (routing) for delivery to remote recipients. In either case it may edit and/or add to the message headers. 58 %Any program responsible for delivering e-mail messages. Upon receiving a message from a Mail User Agent or another MTA, often by SMTP over the Internet, it stores it temporarily locally and analyses the recipients and delivers it to any local addressees and/or forwards it to other remote MTAs (routing) for delivery to remote recipients. In either case it may edit and/or add to the message headers.
59 % 59 %
60 %The most widely used MTA for Unix is sendmail, which communicates using SMTP. 60 %The most widely used MTA for Unix is sendmail, which communicates using SMTP.
61 % 61 %
62 %RFC 2821 (SMTP) expands MTA as ``Mail Transfer Agent'' though this is less common. Alternatives with ``Transport'' are also seen but less correct. 62 %RFC 2821 (SMTP) expands MTA as ``Mail Transfer Agent'' though this is less common. Alternatives with ``Transport'' are also seen but less correct.
63 \citeweb{website:thefreedictionary} 63 \citeweb{website:thefreedictionary}
64 \end{quotation} 64 \end{quote}
65 65
66 Common is the transfer of mail to other machines; this is the actual job. \MTA{}s work with mail, received from local users and/or remote machines. Mail delivery however is \emph{not} what \mta{}s are for, although probably every \MTA\ is able to deliver mail, and many do. \name{mail delivery agents} (short: \NAME{MDA}) are the programs for this job. Two of the best known \NAME{MDA}s are \name{procmail} and \name{maildrop}. 66 Common is the transfer of mail to other machines; this is the actual job. \MTA{}s work with mail, received from local users and/or remote machines. Mail delivery however is \emph{not} what \mta{}s are for, although probably every \MTA\ is able to deliver mail, and many do. \name{mail delivery agents} (short: \NAME{MDA}) are the programs for this job. Two of the best known \NAME{MDA}s are \name{procmail} and \name{maildrop}.
67 67
68 68
69 69
76 76
77 Its author, Allman, sees three reasons for the huge success: the ``sloopy'' approach (accepting badly formed messages); its focus on the routing function; and the flexible configuration (this was important in \sendmail's early days). 77 Its author, Allman, sees three reasons for the huge success: the ``sloopy'' approach (accepting badly formed messages); its focus on the routing function; and the flexible configuration (this was important in \sendmail's early days).
78 \cite[page xviii]{costales97} 78 \cite[page xviii]{costales97}
79 79
80 Others see \sendmail's success more critical. One of them is quoted in the \name{MMDF} FAQs \citeweb{faqs:mmdf}: 80 Others see \sendmail's success more critical. One of them is quoted in the \name{MMDF} FAQs \citeweb{faqs:mmdf}:
81 \begin{quotation} 81 \begin{quote}
82 Sendmail was once compared by one old Internet hand to ``those killer bees that escaped from the laboratory---and now they're everywhere and you can't get rid of 'em''. 82 Sendmail was once compared by one old Internet hand to ``those killer bees that escaped from the laboratory---and now they're everywhere and you can't get rid of 'em''.
83 \end{quotation} 83 \end{quote}
84 He definately hints here at \sendmail's many security vulnerabilities that came to light and on its complexity, in particular its obscure configuration file \path{sendmail.cf}. 84 He definately hints here at \sendmail's many security vulnerabilities that came to light and on its complexity, in particular its obscure configuration file \path{sendmail.cf}.
85 85
86 No matter how \sendmail\ is seen, one must admit its influence on \unix\ emailing programs. Most existing substitutes mimic \sendmail's interface and behavior. Most notable, they create a symbolic link named ``sendmail'' pointing to their own executable. The reason herefor are the many programs assuming an executable called ``sendmail'' on every computer system existing. 86 No matter how \sendmail\ is seen, one must admit its influence on \unix\ emailing programs. Most existing substitutes mimic \sendmail's interface and behavior. Most notable, they create a symbolic link named ``sendmail'' pointing to their own executable. The reason herefor are the many programs assuming an executable called ``sendmail'' on every computer system existing.
87 87
88 \sendmail\ is not only ported to many platforms, even including \name{Microsoft Windows}, but also it is still the prefered \MTA\ on many systems. 88 \sendmail\ is not only ported to many platforms, even including \name{Microsoft Windows}, but also it is still the prefered \MTA\ on many systems.