E-Mail

writing a E-Mail in Sylpheed

E-Mail /ˈiːmɛɪ̯l/ (English. electronics mail, dt. electronic (r) post office/letter), also briefly Mail, designates, a letter-like message transferred on electronic way in computer networks. Eindeutschungen such as E-letter or E-post office, jokeful also„Current post office “, meet so far on little acceptance. Unclear finally is the assigned grammatical sex. While in Germany predominantly the feminine form became generally accepted (the Mail), dominated in Austria and in Switzerland the Neutrum (the Mail).

E-Mail becomes - stillbefore the World Wide Web - as the most important and usually used service of the Internets outstandingly. Over half of the world-wide E-Mail arising in the Internet is however since approx. to attribute 2002 to Spam.

Table of contents

history

before arising E-Mail messages as letter or telegram, later than telexes and fax were conveyed. End of the 1960erThen the triumphant advance of the E-Mail began years - it was one of first applications, which used the possibilities of the ARPANETs. The introduction of E-Mail was planned purposefully, but conquered the network due to the user behavior. This surprised the ARPANETLawrence Robert, the later leader had said initiators, because still 1967 of IPTO, the possibility of the exchange of messages among the network participants was „emergency on important motivation for A network OF scientific computer “ (dt.: „no important motive,Network of scientific computers to construct “). Already 1971 exceeded the total volume of the electronic Mailverkehrs the volume of data, which was completed over telnet and ftp.

As an inventor the computer engineer Ray Tomlinson is considered to the electronic post office. First tests took place 1971, and approximatelyEnd (November od. Decembers) 1971 had the programs (SNDMSG/READMAIL), developed by it, premiere. At that time with the private research enterprise the BBN (Bolt, Beranek and Newman) in Cambridge, Massachusetts, with the structure of the ARPANET busy inventors can however according to own dataany longer does not say exactly, what contents of the first message were. The first letter row of an American computer keyboard „QWERTYUIOP “is however very probable.

Parallel to the Internet years in most networks of systems, with those developed itself at the beginning of the 1980erMessages left transferred. In addition among other things mailbox belonged - systems, X.25, Novell and VTX. These systems were strongly displaced in the middle of the 1990er by the spreading of the Internet. From this time, i.e. from the year 1982, also that originates RFC 822, which for the first time treated the format of text messages in the Arpanet.

In Germany 2 became to. August 1984 those allegedly first Internet enamels receive and sent: The Karlsruher Internet pioneer Werner anger answered the official welcome greeting of the US-American CSNet, of onemanufacturer-spreading platform for electronic communication of scientists.

Today (2006) enamels are transferred predominantly by smtp over Internet and in local area networks, X.400, an open, world-wide standard, are only used beside it still seriously.

The first large group of E-Mail discussions, thosein the ARPANET, was the SF-LOVERS-list developed, in that itself a set of ARPA - researchers at public discussions over Science Fiction took part (Rhine gold, 1994). SF-LOVERS emerged in the late 70's in the ARPANET. First one tried to intervene against it,because such activities had to do few even during most liberal interpretation with research. For some months the list became therefore closed. Finally the responsible persons the ARPA were convinced however with the argument that SF-LOVERS an important pilot project for research thatAdministration and the enterprise of large mailing lists were (hoods, 1993). System engineers had the system repeated changes, so that it could master like an explosion rising the message arising.

technical details

structure of a E-Mail

the format of a E-Mail becomesby the RFC 2822 fixed. Afterwards enamels consist only of text characters. Over computers the forwarding and/or. to facilitate, enamels are internally divided the representation into two parts. For forwarding and/or. Feed substantial part with transmitter and receiver lines is called header. The part with actual contents of the message is called Body.

headers - the head of the E-Mail

major item: Headers (E-Mail)

the headers headlines mentioned of a E-Mail give information over the way, which a E-Mail took,and referring to senders, receivers, date of the production and stations of the transmission offer.

Body - contents of the E-Mail

of the Body of a E-Mail are separate by a blank line from the header and contain the information which can be transmitted inone or more parts.

A E-Mail may do indications of the 7-Bit ASCII in accordance with RFC 2822 section 2,3 only - contain of character set. If other indications or data are being transmitted like for example pictures, these must be coded before suitably . One regulates through RFC 2045 FF (see also MIME and base64). Current Mail Clients codes text and appendices of file (see. down) if necessary automatically.

Apart from the classical plain language partial messages become partly inadvertent and unconscious also as HTML - file dispatched - by the pre-settingthe Mail Clients, partly consciously, in order to be able to use writing honors. Many receivers reject HTML Mail however, since these represent a safety risk when using Javascript or use of other resources. Besides the interpretation of the HTML code is strong from the user environment of theReceiver dependently, whereby optical effects or formatting are frequently not represented in such a way, how this was meant from the sender.

size of

the maximum size of enamels is not limited in principle. In the reality however borders show up by technicalor administrative restrictions of the systems, which transfer or receive the E-Mail. Thus step at present (2005) with enamels off approx. 20 MT size, regularly problems up. In such cases the sender receives an error message.

elementsa E-Mail

the E-Mail address

major item: E-Mail address

a E-Mail address is the indication, which the receiver of a E-Mail clearly designation and so that a feed makes possible to this receiver. A E-Mail address, like it for transport by smtp in the Internetone uses, consists of two parts: A local part, in English local part mentioned and a global part, in English domain part mentioned. Both parts are connected by the RK character (@). With the E-Mail address info@wikipedia.org wikipedia.org is the domain part, info. of the local part.Other transportation mechanisms like e.g.UUCP or X.400 uses another address syntax.

appendices of file

an appendix of file (English. Attachment) is a file, which is sent away in the Body of a E-Mail. This becomes by the MIME - minutes make possible, which the partitioning of theBodys and coding the file regulate. Appendices of file can contain computer viruses, therefore should be gone around carefully with them. The size of a Attachments is in principle not limited, however in the reality by restrictions of size for the entire E-Mail is limited.

dispatch

used minutes

  • smtp are minutes to the Mailversand and - transport.
  • POP3 serves for the call of Mails of a Mailserver.
  • IMAP serves to access mailboxes which lie on Mailservern.
  • SMAP is an advancementof IMAP.
  • UUCP is minutes, with which enamels are collected and with the next connection establishment are sent away. It lost today strongly at meaning.

monitoring

major item: E-Mail monitoring

in the meantime becomes in many countries E-Mail traffic of the state supervised. In Germany 2005 Internet service tenderers are obligated to reproach appropriate hard and software in order to be able to respond to a monitoring arrangement immediately, without receiving for the costs arising from it a financial reconciliation for the year. First Internet service tenderers have already at the end of of 2004 Price increases thereby justifies.

use interface

for production, to the dispatch and to the receipt of enamels gives it several possibilities.

Major item: E-Mail program

for the use of E-Mail can be called, used a E-Mail program, also a E-Mail client or an Mail user agent (MUA). Such a programinstalled and communicated for one or more Mail servers of a Mail Providers on the computer of the user with is.

Major item: Webmail

as alternative procedure for the use of a E-Mail program was established also the use of Webmail. Instead of with a locally installedProgram here the enamels are worked on with a Web Browser on a Web server of the Mail Providers.

pro and cons

the E-Mail system possesses some pro and cons, which are specified in the following.

authenticity and protection of contents

Most E-Mail messages are sent away in the plain language, can be read thus in principle on each computer, which the message on its way from the sender to the receiver passes. If one draws an analogy to the letter post, a E-Mail is therefore rather with a postcardcomparably as with a letter protected by an envelope forwards curious views.

Likewise similarly as with a letter or a postcard and just as simple enamels with a wrong return address can be sent away, which for example with Spam (UCE/PRACTICE) to often observe is. Destination address, CC and BCC addresses can be falsified equally (ADDRESS spoofing).

The solution for these two problems is coding and Absenderauthentifizierung. For this (among other things) the procedures PGP and its free variant GnuPG exist, as well as S/MIME (predominant in the B2B - range), which are however not yet particularly far common. Even such coding procedures cover only contents of the E-Mail, not the line for reference text or the E-Mail date. Thus perhaps conclusions on contents of a coded Mail can are pulled.

has

conclusive force enamel little conclusive force, since the transmitter does not have a possibility with conventional minutes and log mechanisms of proving when he which whom dispatched on and whether the receiver received the E-Mail. Throughan electronic signature and particularly by a qualified electronic signature however commitments can be created in right traffic (civil law, administrative law), which have existence also before court. Colloquially then of one „digital signature “one speaks. Obligatory settinga time stamp under certain conditions likewise one recognizes. Details are regulated in the signature law. The receipt of the message a signature cannot prove however, for this is for example one - ideal-proves likewise marked - to answer necessary. Some Dienstleister offer solutions, thoseSignature, coding and answer automate (for example E-Mail freight service called).

running time

E-Mail was developed, differently than for example telephone or IRC, not for contemporaneous (synchronous) sending and receiving, but is like letter post or fax an asynchronous communication medium- the transmitter can also send its message, if the receiver can receive it not immediately.

The running time of the E-Mail can represent a problem, there it - differently than for example with the fax - is not foreseeable and under unfavorableConditions strongly to vary knows. The fluctuations of the running time are affected by a multiplicity by parameters, particularly by the extent of utilization of the Mailsysteme involved as well as the transmission capacity that which is available for E-Mail the Mailsysteme be-being those lines. The Mailserver of the receiver is longernot attainable, or the Mail will transfer it only in large time intervals to the server of the receiver, can quite to running times of some days come.

Absenderauthentifizierung

in the year 2004 gave it different attempts, the Spam problem to thatTo get grasp. The procedures transmitter ID von Microsoft , Sender Policy Framework ( SPF) competed, DomainKeys of Yahoo!, RMX and AMTP around the favour of the conversion. IETF - Working group tried to define a standard. The function mode participateswith all procedures similarly. By an auxiliary entry in the DNS it should be possible to verfizieren the sending Mailserver. The IETF working group failed however finally because of unsettled patent claims on the part of Microsoft. The different procedures are now in own procedures as RFCs are converted.

see also

Web on the left of

Wiktionary: E-Mail - word origin, synonyms and translations
 

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