"ఈ-మెయిల్" కూర్పుల మధ్య తేడాలు

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సవరణ సారాంశం లేదు
చి (Wikipedia python library)
 
ఎలక్ట్రానిక్ ఉత్తరము లో రెండు భాగాలు ఉంటాయి, హెడర్, మరియు బాడీ. బాడీ అనగా ఉత్తరము లో మనము పంపించే సారాంశము. హెడర్ లో ఉత్తరము పంపించిన వారి ఈ-మెయిల్ అడ్రస్, ఒకటి లేదా అంతకన్నా ఎక్కువగా ఉత్తరము అందుకొంటున్న వారి ఈ-మెయిలు అడ్రస్ ఉంటాయి. అలానే, ఉత్తర సారాంశమును తెలిపే సబ్జెక్టు కూడా ఉంటుంది.
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The foundation for today's global Internet e-mail service was created in the early [[ARPANET]] and standards for encoding of messages were proposed as early as, for example, in 1973 (RFC 561). An e-mail sent in the early 1970s looked very similar to one sent on the Internet today. Conversion from the ARPANET to the Internet in the early 1980s produced the core of the current service.
 
Network-based email was initially exchanged on the ARPANET in extensions to the [[File Transfer Protocol]] (FTP), but is today carried by the [[Simple Mail Transfer Protocol]] (SMTP), first published as [[Internet Standard]] 10 (RFC 821) in 1982. In the process of transporting email messages between systems, SMTP communicates delivery parameters using a message ''envelope'' separately from the message (headers and body) itself.
 
Originally a text-only communications medium, email was extended to carry multi-media content attachments, which were standardized in 1996 with RFC 2045 through RFC 2049, collectively called, [[Multipurpose Internet Mail Extensions]] (MIME).
 
E-mail systems are based on a [[store-and-forward]] model in which e-mail computer server systems accept, forward, deliver and store messages on behalf of users, who only need to connect to the e-mail infrastructure, typically an e-mail server, with a network-enabled device (e.g., a personal computer) for the duration of message submission or retrieval. Rarely is e-mail transmitted directly from one user's device to another's.
 
== Spelling ==
The [[spelling]] variations ''e-mail'' and ''email'' are both common. Several prominent journalistic and technical [[style guide]]s recommend ''e-mail'',<ref>{{cite web|url=http://www.chicagomanualofstyle.org/CMS_FAQ/HyphensEnDashesEmDashes/HyphensEnDashesEmDashes05.html|title=Hyphens, En Dashes, Em Dashes - Q&A|accessdate=2008-05-18}}</ref><ref>[http://safari.oreilly.com/0735617465 O'Reilly - Safari Books Online - 0735617465 - Microsoft Manual of Style for Technical Publications Third Edition]</ref><ref>[http://standards.ieee.org/guides/style/annexa.html 2007 IEEE Standards Style Manual-Annex A]</ref><ref name=APStyleBook>[http://www.apstylebook.com/ask_editor.php APStylebook.com]</ref> and the spelling ''email'' is also recognized in many dictionaries.<ref>[http://dictionary.reference.com/browse/email Reference.com]</ref><ref>Random House Unabridged Dictionary, 2006</ref><ref>The American Heritage Dictionary of the English Language, Fourth Edition</ref><ref>Princeton University WordNet 3.0</ref><ref>The American Heritage Science Dictionary, 2002</ref> In the original [[Request for Comments|RFC]] neither spelling is used; the service is referred to as ''mail'', and a single piece of electronic mail is called a ''message''.<ref>[http://www.faqs.org/rfcs/rfc821.html RFC 821 (rfc821) - Simple Mail Transfer Protocol]</ref><ref name="11above">[http://www.faqs.org/rfcs/rfc1939.html RFC 1939 (rfc1939) - Post Office Protocol - Version 3 ]</ref><ref name="12above">[http://www.faqs.org/rfcs/rfc3501.html RFC 3501 (rfc3501) - Internet Message Access Protocol - version 4rev1 ]</ref> The plural form "e-mails" (or emails) is also recognized.<ref name=APStyleBook/>
 
Newer RFCs and [[IETF]] working groups require ''email'' for consistent capitalization, hyphenation, and spelling of terms<ref>{{cite web |url=http://www.rfc-editor.org/rfc-style-guide/rfc-style-manual-08.txt |title=RFC Document Style |accessdate=2008-11-24 |author=R. Braden |coauthors=S. Ginoza; A. Hagens |date=2007-11-30 |work=Style Guide |publisher=[[RFC Editor]]}} That refers to [http://www.rfc-editor.org/rfc-style-guide/terms-online-03.txt terms-online] that explicitly requires ''email'' spelling.</ref>. [[ARPANET]] users and early developers from [[Unix]], [[CMS]], [[AppleLink]], [[eWorld]], [[AOL]], [[GEnie]], and [[HotMail]] used ''eMail'' with the letter ''M'' capitalized. The authors of some of the original RFCs used ''eMail'' when giving their own addresses.<ref name="11above"/><ref name="12above"/>
 
[[Donald Knuth]] considers the spelling "e-mail" to be archaic and notes that it is more often spelled "email" in the UK. In some other European languages (French, German, Dutch, Romanian), "email" (ignoring diacritics) is the word for "enamel".<ref>http://www-cs-faculty.stanford.edu/~knuth/email.html - this page is undated but has been in the [[Internet Archive]] since 1997 (with a time stamp of 1996), and may be as old as 1991 according to [http://www.webmasterworld.com/content_copywriting/3107680.htm a blog post]</ref>
 
== ఆరంభం ==
{{Expand-section|date=September 2008}}
E-mail predates the inception of the [[Internet]], and was in fact a crucial tool in creating the Internet.
 
[[Massachusetts Institute of Technology|MIT]] first demonstrated the [[Compatible Time-Sharing System]] (CTSS) in 1961.<ref>
"CTSS, Compatible Time-Sharing System" (September 4, 2006),
University of South Alabama, web:
[http://www.cis.usouthal.edu/faculty/daigle/project1/ctss.htm USA-CTSS].
</ref> It allowed multiple users to log into the [[IBM 7094]]<ref>
[[Tom Van Vleck]], "The IBM 7094 and CTSS" (September 10, 2004), ''Multicians.org''
([[Multics]]), web: [http://www.multicians.org/thvv/7094.html Multicians-7094].
</ref> from remote dial-up terminals, and to store files online on disk. This new ability encouraged users to share information in new ways. E-mail started in 1965 as a way for multiple users of a [[time-sharing]] [[mainframe computer]] to communicate. Although the exact history is murky, among the first systems to have such a facility were [[System Development Corporation|SDC's]] [[Q32]] and MIT's CTSS.
 
E-mail was quickly extended to become ''network e-mail'', allowing users to pass messages between different computers by 1966 or earlier (it is possible that the [[Semi Automatic Ground Environment|SAGE]] system had something similar some time before).
 
The [[ARPANET]] [[computer network]] made a large contribution to the development of e-mail. There is one report that indicates experimental inter-system e-mail transfers began shortly after its creation in 1969.<ref>[http://www.multicians.org/thvv/mail-history.html The History of Electronic Mail ]</ref> [[Ray Tomlinson]] initiated the use of the "[[At sign|@]]" sign to separate the names of the user and their machine in 1971.<ref>[http://openmap.bbn.com/~tomlinso/ray/firstemailframe.html The First Email ]</ref> The [[ARPANET]] significantly increased the popularity of e-mail, and it became the [[Killer application|killer app]] of the ARPANET.
 
Most other networks had their own email protocols and [[Email address|address]] formats; as the influence of the [[ARPANET]] and later the Internet grew, central sites often hosted email gateways that passed mail between the Internet and these other networks. Internet email addressing is still complicated by the need to handle mail destined for these older networks. Some well-known examples of these were [[UUCP]] (mostly Unix computers), [[BITNET]] (mostly IBM and VAX mainframes at universities), [[FidoNet]] (personal computers), and DECNET (various networks).
 
An example of an Internet email address that routed mail to a user at a UUCP host:
<pre>
hubhost!middlehost!edgehost!user@uucpgateway.somedomain.example.com
</pre>
 
This was necessary because in early years UUCP computers did not maintain (or consult servers for) information about the location of all hosts they exchanged mail with, but rather only knew how to communicate with a few network neighbors; email messages (and other data such as [[Usenet|Usenet News]]) were passed along in a chain among hosts who had explicitly agreed to share data with each other.
 
== పనిచేయు విధానం ==
కుడి ప్రక్క చుపిన పటంలో అలీస్ మెయిల్ యుజర్ ఏజెంట్ ([[E-mail client|mail user agent]] (MUA)). ఉపయొగించి మెసెజ్ కంపొజ్ చెసెటప్పుడు జరిగె పరిణమాన్ని చూపించటమైనది. అలీస్([[Placeholder names in cryptography|Alice]] ) తన ఇ-మెయిల్ అడ్రస్ ([[e-mail address]]) టైప్ చేసి “send” బటన్ నోక్కినప్పుడు ఈ క్రిందవి జరుగుతాయి.
<ref>{{cite video | title = How E-mail Works | medium = internet video | publisher = howstuffworks.com | year = 2008 | url = http://www.webcastr.com/videos/informational/how-email-works.html}}</ref>
<span style="float:right">[[దస్త్రం:email.svg|400px|How e-mail works]]</span>
# Her MUA formats the message in e-mail format and uses the [[Simple Mail Transfer Protocol]] (SMTP) to send the message to the local [[mail transfer agent]] (MTA), in this case <tt>smtp.a.org</tt>, run by Alice's [[Internet Service Provider]] (ISP).
# The MTA looks at the destination address provided in the SMTP protocol (not from the message header), in this case <tt>bob@b.org</tt>. An Internet e-mail address is a string of the form <tt>localpart@exampledomain</tt>. The part before the @ sign is the '''local part''' of the address, often the [[username]] of the recipient, and the part after the @ sign is a [[domain name]] or a [[fully qualified domain name]]. The MTA resolves a domain name to determine the fully qualified domain name of the [[mail exchange server]] in the [[Domain Name System]].
# The [[DNS server]] for the <tt>b.org</tt> domain, <tt>ns.b.org</tt>, responds with any [[MX record]]s listing the mail exchange servers for that domain, in this case <tt>mx.b.org</tt>, a server run by Bob's ISP.
# <tt>smtp.a.org</tt> sends the message to <tt>mx.b.org</tt> using SMTP, which delivers it to the [[Email Mailbox|mailbox]] of the user <tt>bob</tt>.
# Bob presses the "get mail" button in his MUA, which picks up the message using the [[Post Office Protocol]] (POP3).
 
That sequence of events applies to the majority of e-mail users. However, there are many alternative possibilities and complications to the e-mail system:
* Alice or Bob may use a client connected to a corporate e-mail system, such as [[IBM]] [[Lotus Notes]] or [[Microsoft]] [[Microsoft Exchange Server|Exchange]]. These systems often have their own internal e-mail format and their clients typically communicate with the e-mail server using a vendor-specific, proprietary protocol. The server sends or receives e-mail via the Internet through the product's Internet mail gateway which also does any necessary reformatting. If Alice and Bob work for the same company, the entire transaction may happen completely within a single corporate e-mail system.
* Alice may not have a MUA on her computer but instead may connect to a [[webmail]] service.
* Alice's computer may run its own MTA, so avoiding the transfer at step 1.
* Bob may pick up his e-mail in many ways, for example using the [[Internet Message Access Protocol]], by logging into <tt>mx.b.org</tt> and reading it directly, or by using a [[webmail]] service.
* Domains usually have several mail exchange servers so that they can continue to accept mail when the main mail exchange server is not available.
* E-mail messages are not secure if [[e-mail encryption]] is not used correctly.
 
Many MTAs use to accept messages for any recipient on the Internet and do their best to deliver them. Such MTAs are called ''[[open mail relay]]s''. This was very important in the early days of the Internet when network connections were unreliable. If an MTA couldn't reach the destination, it could at least deliver it to a relay closer to the destination. The relay stood a better chance of delivering the message at a later time. However, this mechanism proved to be exploitable by people sending [[e-mail spam|unsolicited bulk e-mail]] and as a consequence very few modern MTAs are open mail relays, and many MTAs don't accept messages from open mail relays because such messages are very likely to be spam.
 
== మెస్సేజ్ ఫార్మాట్ ==
The Internet e-mail message format is defined in RFC 5322 and a series of [[Request for Comments|RFCs]], RFC 2045 through RFC 2049, collectively called, ''[[Multipurpose Internet Mail Extensions]]'', or ''MIME''. Although as of July 13, 2005, RFC 2822 is technically a proposed [[Internet Engineering Task Force|IETF]] standard and the MIME RFCs are draft IETF standards,<ref>{{citeweb|title=RFC Index|url=http://www.ietf.org/iesg/1rfc_index.txt}}</ref> these documents are the standards for the format of Internet e-mail. Prior to the introduction of RFC 2822 in 2001, the format described by RFC 822 was the standard for Internet e-mail for nearly 20 years; it is still the official IETF standard. The IETF reserved the numbers 5321 and 5322 for the updated versions of RFC 2821 (SMTP) and RFC 2822, as it previously did with RFC 821 and RFC 822, honoring the extreme importance of these two RFCs. RFC 822 was published in 1982 and based on the earlier RFC 733 (see<ref>Ken Simpson, "An update to the email standards" (October 3, 2008), ''blog.mailchannels.com'', web: [http://blog.mailchannels.com/2008/10/update-to-email-standards.html MailChannels Blog Entry].
</ref>).
 
Internet e-mail messages consist of two major sections:
* Header — Structured into [[Field (computer science)|fields]] such as summary, sender, receiver, and other information about the e-mail.
* Body — The message itself as unstructured text; sometimes containing a [[signature block]] at the end. This is exactly the same as the body of a regular letter.
 
The header is separated from the body by a blank line.
 
=== మెస్సేజ్ హెడ్డర్ ===
 
 
Each message has exactly one [[Header (computing)|header]], which is structured into [[Field (computer science)|fields]]. Each field has a name and a value. RFC 5322 specifies the precise syntax.
 
Informally, each line of text in the header that begins with a [[ASCII#ASCII printable characters|printable character]] begins a separate field. The field name starts in the first character of the line and ends before the separator character ":". The separator is then followed by the field value (the "body" of the field). The value is continued onto subsequent lines if those lines have a space or tab as their first character. Field names and values are restricted to 7-bit [[ASCII]] characters. Non-ASCII values may be represented using MIME [[MIME#Encoded-Word|encoded words]].
 
==== హెడ్డర్ ఫీల్డ్స్ ====
The message header should include at least the following fields:
* From: The [[e-mail address]], and optionally the name of the sender. In many e-mail clients not changeable except through changing account settings.
* To: The e-mail address(es), and optionally name(s) of the message's recipient(s). Indicates primary recipients (multiple allowed), for secondary recipients see Cc: and Bcc: below.
* Subject: A brief summary of the contents of the message.
* Date: The local time and date when the message was written. Like the ''From:'' field, many email clients fill this in automatically.
* Message-ID: Also an automatically generated field; used to prevent multiple delivery and for reference in In-Reply-To: (see below).
 
Note that the "To:" field is not necessarily related to the addresses to which the message is delivered. The actual delivery list is supplied separately to the transport protocol, [[SMTP]], which may or may not originally have been extracted from the header content. The "To:" field is similar to the addressing at the top of a conventional letter which is delivered according to the address on the outer envelope. Also note that the "From:" field does not have to be the real sender of the e-mail message. One reason is that it is very easy to fake the "From:" field and let a message seem to be from any mail address. It is possible to [[Digital signature|digitally sign]] e-mail, which is much harder to fake, but such signatures require extra programming and often external programs to verify. Some [[Internet service provider]]s do not relay e-mail claiming to come from a domain not hosted by them, but very few (if any) check to make sure that the person or even e-mail address named in the "From:" field is the one associated with the connection. Some [[Internet service provider]]s apply [[e-mail authentication]] systems to e-mail being sent through their [[MTA]] to allow other MTAs to detect forged spam that might appear to come from them.
 
Other common header fields include (see RFC 4021 or RFC 2076 for more):
* Bcc: [[Blind Carbon Copy]]; addresses added to the SMTP delivery list but not (usually) listed in the message data, remaining invisible to other recipients.
* Cc: [[Carbon copy]]; Many e-mail clients will mark e-mail in your inbox differently depending on whether you are in the To: or Cc: list.
* [[Content-Type]]: Information about how the message is to be displayed, usually a [[MIME]] type.
* In-Reply-To: [[Message-ID]] of the message that this is a reply to. Used to link related messages together.
* Precedence: commonly with values "bulk", "junk", or "list"; used to indicate that should automated "vacation" or "out of office" responses should not be returned for this mail, eg. to prevent vacation notices from being sent to all other subscribers of a mailinglist.
* Received: Tracking information generated by mail servers that have previously handled a message, in reverse order (last handler first).
* References: [[Message-ID]] of the message that this is a reply to, and the message-id of the message the previous was reply a reply to, etc.
* Reply-To: Address that should be used to reply to the sender.
* Sender: Address of the actual sender acting on order of the address-owner listed in the To: field (secretary, list manager, etc.).
* [[X-Face]]: Small icon.
 
[[Internet Assigned Numbers Authority|IANA]] maintains [http://www.iana.org/assignments/message-headers/perm-headers.html a list of standard header fields].
 
=== సందేశ శరీరం ===
{{Refimprovesect|date=November 2007}}
 
==== కంటెంట్ ఎన్కోడింగ్ ====
E-mail was originally designed for 7-bit [[ASCII]].<ref>{{citebook|title=TCP/IP Network Administration|year=2002|isbn=978-0596002978|author=Craig Hunt|publisher=[[O'Reilly Media]]|pages=70}}</ref> Much e-mail software is [[8-bit clean]] but must assume it will communicate with 8-bit servers and mail readers. The [[MIME]] standard introduced character set specifiers and two content transfer encodings to enable transmission of non-ASCII data: [[quoted printable]] for mostly 7 bit content with a few characters outside that range and [[base64]] for arbitrary binary data. The [[8BITMIME]] extension was introduced to allow transmission of mail without the need for these encodings but many [[mail transport agent]]s still do not support it fully. In some countries, several encoding schemes coexist; as the result, by default, the message in a non-Latin alphabet language appears in non-readable form (the only exception is coincidence, when the sender and receiver use the same encoding scheme). Therefore, for international [[character set]]s, [[Unicode]] is growing in popularity.
 
==== ప్లైయిన్ సందేశం మరియు హెచ్ టి ఎమ్ ఎల్ ====
Both [[plain text]] and [[HTML]] are used to convey e-mail. While text is certain to be read by all users without problems, there is a perception{{Fact|date=June 2009}} that [[HTML e-mail|HTML-based e-mail]] has a higher aesthetic value, assuming the recipient uses an e-mail client that will properly show the HTML markup. This is not always the case, especially among the technological savvy and bandwidth-constrained users. Advantages of HTML include the ability to include inline links and images, set apart previous messages in [[block quote]]s, wrap naturally on any display, use emphasis such as [[underline]]s and [[italics]], and change [[font]] styles. HTML e-mail messages often include an automatically-generated plain text copy as well, for compatibility reasons. Disadvantages include the increased size of the email, privacy concerns about [[web bug]]s, abuse of HTML email as a vector for [[phishing]] attacks and the spread of [[malware|malicious software]].<ref>{{citeweb|title=Email policies that prevent viruses|url=http://advosys.ca/papers/mail-policies.html}}</ref>
 
== Servers and client applications ==
[[దస్త్రం:Mozilla thunderbird empty screenshot.png|thumb|right|300px|The interface of an e-mail client, [[Mozilla Thunderbird|Thunderbird]].]]
 
Messages are exchanged between hosts using the [[SMTP|Simple Mail Transfer Protocol]] with software programs called [[mail transfer agent]]s. Users can retrieve their messages from servers using standard protocols such as [[Post Office Protocol|POP]] or [[IMAP]], or, as is more likely in a large [[corporation|corporate]] environment, with a [[Proprietary software|proprietary]] protocol specific to [[Lotus Notes]] or [[Microsoft Exchange Server]]s. [[Webmail]] interfaces allow users to access their mail with any standard [[web browser]], from any computer, rather than relying on an e-mail client.
 
Mail can be stored on the [[client (computing)|client]], on the [[Server (computing)|server]] side, or in both places. Standard formats for mailboxes include [[Maildir]] and [[mbox]]. Several prominent e-mail clients use their own proprietary format and require conversion software to transfer e-mail between them.
 
Accepting a message obliges an MTA to deliver it, and when a message cannot be delivered, that MTA must send a [[bounce message]] back to the sender, indicating the problem.
 
=== కవిల(ఫైలు) పేర్లు మరియు పొడిగింతలు ===
Upon reception of e-mail messages, e-mail client applications save message in operating system files in the filesystem. Some clients save individual messages as separate files, while others use various database formats, often proprietary, for collective storage. A historical standard of storage is the ''[[mbox]]'' format. The specific format used is often indicated by special [[filename extension]]s:{{Expand|date=May 2009}}
;<tt>.eml</tt>
:This is the default e-mail file extension for [[Mozilla Thunderbird]] and [[Windows Mail]]. It is also used by [[Outlook Express|Microsoft Outlook Express]].
;<tt>.emlx</tt>
:Used by [[Mail (application)|Apple Mail]].
;<tt>.msg</tt>
:Used by [[Microsoft Outlook|Microsoft Office Outlook]].
;<tt>.mbx</tt>
:Used by [[Opera Mail]], [[KMail]], and [[Mail (application)|Apple Mail]] based on the [[mbox]] format.
 
Some applications (like [[Mail (application)|Apple Mail]]) also encode attachments into messages for searching while also producing a physical copy of the files on a disk. Others separate attachments from messages by depositing them into designated folders on disk.
 
=== URI scheme ''mailto:'' ===
The [[URI scheme]], as registered with the [[Internet Assigned Numbers Authority|IANA]], defines the <tt>mailto:</tt> scheme for SMTP email addresses. Though its use is not strictly defined, URLs of this form are intended to be used to open the new message window of the user's mail client when the URL is activated, with the address as defined by the URL in the "To:" field.
<ref>
RFC 2368 section 3 : by Paul Hoffman in 1998 discusses operation of the "mailto" URL.
</ref>
 
== ఉపయోగం ==
{{Refimprovesect|date=November 2007}}
 
=== సమాజంలో ===
There are numerous ways in which people have changed the way they communicate in the last 50 years; e-mail is certainly one of them. Traditionally, social interaction in the local community was the basis for communication – face to face. Yet, today face-to-face meetings are no longer the primary way to communicate as one can use a landline telephone or any number of the computer mediated communications such as e-mail.
 
Research has shown that people actively use e-mail to maintain core social networks, particularly when alters live at a distance. However, contradictory to previous research, the results suggest that increases in Internet usage are associated with decreases in other modes of communication, with proficiency of Internet and e-mail use serving as a mediating factor in this relationship. <ref>Stern, Michael J.Information, Communication & Society; Oct2008, Vol. 11 Issue 5, p591-616, 26p. CLB Oklahoma State University, Stillwater, OK, USA. </ref>
 
==== Flaming ====
[[Flaming (Internet)|Flaming]] occurs when a person sends a message with angry or antagonistic content. Flaming is assumed to be more common today because of the ease and impersonality of e-mail communications: confrontations in person or via telephone require direct interaction, where social norms encourage civility, whereas typing a message to another person is an indirect interaction, so civility may be forgotten.{{Fact|date=June 2009}} Flaming is generally looked down upon by Internet communities as it is considered rude and non-productive.
 
==== ఈ-మెయిల్ దివాళా ====
Also known as "ఈ-మెయిల్ అలసట", ఈ-మెయిల్ దివాళా is when a user ignores a large number of e-mail messages after falling behind in reading and answering them. The reason for falling behind is often due to information overload and a general sense there is so much information that it is not possible to read it all. As a solution, people occasionally send a boilerplate message explaining that the e-mail inbox is being cleared out. [[Stanford University]] law professor [[Lawrence Lessig]] is credited with coining this term, but he may only have popularized it.<ref>{{cite news |title=All We Are Saying. |url=http://www.nytimes.com/2007/12/23/weekinreview/23buzzwords.html?ref=weekinreview |publisher=[[New York Times]] |date=[[December 23]] [[2007]]|accessdate=2007-12-24 }}</ref>
 
=== వ్యాపారంలో ===
E-mail was widely accepted by the business community as the first broad electronic communication medium and was the first ‘e-revolution’ in business communication. E-mail is very simple to understand and like postal mail, e-mail solves two basic problems of communication: logistics and synchronization (see below).
LAN based email is also an emerging form of usage for business. It not only allows the business user to download mail when ''offline'', it also provides the small business user to have multiple users e-mail ID's with just ''one e-mail connection''.
 
==== లాభాలు ====
* '''The problem of logistics'''
 
Much of the business world relies upon communications between people who are not physically in the same building, area or even country; setting up and attending an in-person meeting, [[telephone call]], or [[conference call]] can be inconvenient, time-consuming, and costly. E-mail provides a way to exchange information between two or more people with no set-up costs and that is generally far less expensive than physical meetings or phone calls.
 
* '''The problem of synchronization'''
 
With [[Real-time computing|real time]] communication by meetings or phone calls, participants have to work on the same schedule, and each participant must spend the same amount of time in the meeting or call. E-mail allows [[asynchrony]]: each participant may control their schedule independently.
 
==== నష్టాలు ====
{{Original research|section|date=June 2009}}
Most business workers today spend from one to two hours of their working day on e-mail: reading, ordering, sorting, ‘re-contextualizing’ fragmented information, and writing e-mail.<ref>{{Cite web|url= http://www.smallbiztrends.com/2007/06/email-has-right-to-privacy-why-small-businesses-care.html|title= Email Right to Privacy - Why Small Businesses Care| date=2007-06-19| publisher= Anita Campbell}}</ref> The use of e-mail is increasing due to increasing levels of globalization—labour division and outsourcing amongst other things. E-mail can lead to some well-known problems:
* '''Loss of Context''': which means that the context is lost forever , there is no way to get the text back.
Information in context (as in a newspaper) is much easier and faster to understand than unedited and sometimes unrelated fragments of information. Communicating in context can only be achieved when both parties have a full understanding of the context and issue in question.
* '''Information overload''': E-mail is a [[push technology]]—the sender controls who receives the information. Convenient availability of [[mailing list]]s and use of "copy all" can lead to people receiving unwanted or irrelevant information of no use to them.
* '''Inconsistency''': E-mail can duplicate information. This can be a problem when a large team is working on documents and information while not in constant contact with the other members of their team.
 
Despite these disadvantages, e-mail has become the most widely used medium of communication within the business world.
 
== అపరిష్కృత సమస్యలు ==
{{Refimprovesect|date=November 2007}}
 
=== అతి సమాచారం ===
A December 2007 [[New York Times]] blog post described E-mail as "a $650 Billion Drag on the Economy"<ref>{{Cite web|url= http://bits.blogs.nytimes.com/2007/12/20/is-information-overload-a-650-billion-drag-on-the-economy|title= Is Information Overload a $650 Billion Drag on the Economy?| date=2007-12-20| publisher= New York Times}}</ref>, and the New York Times reported in April 2008 that "E-MAIL has become the bane of some people’s professional lives" due to information overload, yet "none of the current wave of high-profile Internet start-ups focused on e-mail really eliminates the problem of e-mail overload because none helps us prepare replies".<ref>{{Cite web|url= http://www.nytimes.com/2008/04/20/technology/20digi.html?_r=2&oref=slogin&oref=slogin|title= Struggling to Evade the E-Mail Tsunami| date=2008-04-20| publisher= New York Times}}</ref>
 
Technology investors reflect similar concerns.<ref>{{Cite web|url= http://www.foundrygroup.com/blog/archives/2008/04/did-darwin-skip-over-email.php|title= Did Darwin Skip Over Email?| date=2008-04-28| publisher= Foundry Group}}</ref>
 
=== చెత్త వేగులు, వైరస్లు ===
The usefulness of e-mail is being threatened by four phenomena: [[ఈ-మెయిల్ bomb]]ardment, [[ఈ-మెయిల్ spam|spamming]], [[phishing]], and [[ఈ-మెయిల్ worm]]s.
 
Spamming is unsolicited commercial (or bulk) e-mail. Because of the very low cost of sending e-mail, spammers can send hundreds of millions of e-mail messages each day over an inexpensive Internet connection. Hundreds of active spammers sending this volume of mail results in [[information overload]] for many computer users who receive voluminous unsolicited e-mail each day.<ref name="R"> Rich Kawanagh. The top ten e-mail spam list of 2005.
 
ITVibe news, 2006, january 02, http://itvibe.com/news/3837/
</ref><ref>avalanche of Viagra ads and Rolex pitches http://dir.salon.com/story/tech/feature/2005/01/19/microsoft_spam/index.html
</ref>
 
ఈ-మెయిల్ worms use e-mail as a way of replicating themselves into vulnerable computers. Although the [[Morris (computer worm)|first e-mail worm]] affected [[UNIX]] computers, the problem is most common today on the more popular [[Microsoft Windows]] operating system.
 
The combination of spam and worm programs results in users receiving a constant drizzle of junk e-mail, which reduces the usefulness of e-mail as a practical tool.
 
A number of [[anti-spam techniques (e-mail)|anti-spam techniques]] mitigate the impact of spam. In the [[United States]], [[Congress of the United States|U.S. Congress]] has also passed a law, the [[Can Spam Act of 2003]], attempting to regulate such e-mail. Australia also has very strict spam laws restricting the sending of spam from an Australian ISP,<ref>{{citeweb|title=Spam Bill 2003|url=http://www.aph.gov.au/library/pubs/bd/2003-04/04bd045.pdf|format=PDF}}</ref> but its impact has been minimal since most spam comes from regimes that seem reluctant to regulate the sending of spam.
 
=== ఈ-మెయిల్ spoofing ===
[[ఈ-మెయిల్ spoofing]] occurs when the header information of an email is altered to make the message appear to come from a known or trusted source. It is often used as a ruse to collect personal information.
 
=== ఈ-మెయిల్ బాంబింగ్ ===
ఉద్దేశపూర్వకంగా ఒక అడ్రసుకు పెద్ద పరిమాణం గల సందేశాలను పంపించుటను [[ఈ-మెయిల్ బాంబింగ్]] అంటారు. ఆధికంగా సందేశాలను నింపటం వలన ఆ ఈ-మెయిల్ అడ్రసు ఉపయోగించని విదముగా అవుతుంది మరియు మెయిల్ సర్వర్ పాడైపోవటానికి కారణం అవుతుంది.
 
=== గోప్యతా సమస్యలు ===
{{main|ఈ-మెయిల్ privacy}}
* ఈ-మెయిల్ సందేశాలు సాధారణంగా ఎన్ క్రిప్టు చేయబడవు;
* ఈ-మెయిల్ సందేశాలు గమ్యస్థానానికి చేరుటకు మార్గమధ్యంలోని కంప్యూటర్ల ద్వారా వెళ్లాలి, అంటే ఇతరులు సులభంగా సందేశాలను అడ్డుకొని చదవగలరు;
* చాలా మంది ఇంటర్నెట్ సర్వీస్ ప్రొవైడర్లు ఈ-మెయిల్ ప్రతులను బట్వాడా చేయుతటకు ముందు తమ సర్వర్లలో దాచుకొనుదురు. మెయిల్ బాక్స్ నుండి మెయిల్ తొలగించినప్పటికీ ఈ బ్యాక్ అప్ లు తమ సర్వర్లలో కొన్ని నెలల పాటు అలానే ఉండి పోతాయి.
* the Received: fields and other information in the e-mail can often identify the sender, preventing anonymous communication.
 
There are [[cryptography]] applications that can serve as a remedy to one or more of the above. For example, [[Virtual Private Network]]s or the [[Tor (anonymity network)|Tor anonymity network]] can be used to encrypt traffic from the user machine to a safer network while [[GNU Privacy Guard|GPG]], [[Pretty Good Privacy|PGP]], SMEmail <ref> Mohsen Toorani, [http://ieeexplore.ieee.org/xpl/freeabs_all.jsp?arnumber=4783292 SMEmail - A New Protocol for the Secure E-mail in Mobile Environments], Proceedings of the Australian Telecommunications Networks and Applications Conference (ATNAC'08), pp.39-44, Adelaide, Australia, December 2008.</ref> , or [[S/MIME]] can be used for [[end-to-end]] message encryption, and SMTP STARTTLS or SMTP over [[Transport Layer Security]]/Secure Sockets Layer can be used to encrypt communications for a single mail hop between the SMTP client and the SMTP server.
 
Additionally, many [[mail user agent]]s do not protect logins and passwords, making them easy to intercept by an attacker. Encrypted authentication schemes such as [[Simple Authentication and Security Layer|SASL]] prevent this.
 
Finally, attached files share many of the same hazards as those found in [[Peer-to-peer|peer-to-peer filesharing]]. Attached files may contain [[Trojan horse (computing)|trojans]] or [[Computer virus|viruses]].
-->
 
=== పంపిన ఉత్తరం చేరిందో లేదో చూడటం ===
మొట్టమొదట వచ్చిన SMTP మెయిల్ సర్విసులో పంపిన ఉత్తరము వెళ్ళే మార్గము తెలుసుకోవడానికి చాలా తక్కువ విధానాలు ఉండేవి. ఉత్తరము చేరిందో లేదో కూడా అవతల వారు సమాధానము ఇచ్చే దాక తెలిసేది కాదు. ఇది ఒక రకంగా లాభం అయితే,(సమాధానం చెప్పడం ఇష్టం లేక పొతే ఉత్తరం అందలేదు అని తప్పించుకోవచ్చు), మరొక విధం గా చాల పెద్ద ఇబ్బంది. అత్యవసరమైనవి, ముఖ్యమైనవి చేరాయో లేదో తెలియక, అలానే, చదవకూడని వాడి చేతి లో అది పడిందేమో అని ఆందోళన, ఇలా వుండేది. ప్రతి మెయిల్ సర్వర్ వుత్తరం అందజేయాలి, లేదా అందచేయలేదు అని తిరిగు సమాధానం చెప్పాలి. చాల మటుకు, సాఫ్టువేరు లో తప్పులతోను, లేదా చతికిలపడ్డ సర్వర్ల మూలంగా ఇవి జరిగేవి కాదు. ఐ పరిస్థితిని కెక్క దిద్దడము కోసము, [[ఇంటర్నెట్ ఇంజనీరింగ్ టాస్క్ ఫోర్స్|IETF]] వారు [[డెలివరీ స్టేటస్ నోటిఫికేషన్]] లను (డెలివరీ రేసీప్ట్) మరియు [[రిటర్న్ రేసీప్ట్#ఈ-మెయిల్|ఉత్తరము పంపించే నోటిఫికేషన్స్]] (రిటర్న్ రేసీప్ట్] లను ప్రవేశ పెట్టారు. అయితే, వీటిని అమలుపరచలేదు.
<!--
== అమెరికా ప్రభుత్వం ==
The US Government has been involved in ఈ-మెయిల్ in several different ways.
 
Starting in 1977, the [[US Postal Service]] (USPS) recognized that electronic mail and electronic transactions posed a significant threat to First Class mail volumes and revenue. Therefore, the USPS initiated an experimental e-mail service known as E-COM. Electronic messages were transmitted to a post office, printed out, and delivered as hard copy. To take advantage of the service, an individual had to transmit at least 200 messages. The delivery time of the messages was the same as First Class mail and cost 26 cents. Both the [[Postal Regulatory Commission]] and the [[Federal Communications Commission]] opposed E-COM. The FCC concluded that E-COM constituted common carriage under its jurisdiction and the USPS would have to file a [[tariff]].<ref>In re Request for declaratory ruling and investigation by Graphnet Systems, Inc., concerning the proposed E-COM service, FCC Docket No. 79-6 (September 4, 1979)</ref> Three years after initiating the service, USPS canceled E-COM and attempted to sell it off.<ref>[http://www.usps.com/history/history/his1.htm History of the United States Postal Service, USPS]</ref><ref>Hardy, Ian R; The Evolution of ARPANET Email; 1996-05-13; History Thesis; University of California at Berkeley</ref><ref>James Bovard, The Law Dinosaur: The US Postal Service, CATO Policy Analysis (February 1985) </ref><ref>[http://www.cs.ucsb.edu/~almeroth/classes/F04.176A/homework1_good_papers/jay-akkad.html Jay Akkad, The History of Email]</ref><ref>[http://www.cybertelecom.org/notes/email.htm Cybertelecom : Email]</ref><ref>[http://www.gao.gov/archive/2000/gg00188.pdf US Postal Service: Postal Activities and Laws Related to Electronic Commerce, GAO-00-188 ]</ref><ref>[http://govinfo.library.unt.edu/ota/Ota_4/DATA/1982/8214.PDF Implications of Electronic Mail and Message Systems for the U.S. Postal Service , Office of Technology Assessment, Congress of the United States, August 1982]</ref>
 
The early [[ARPANET]] dealt with multiple e-mail clients that had various, and at times incompatible, formats. For example, in the system Multics, the "@" sign meant "kill line" and anything after the "@" sign was ignored.<ref>[http://www.cs.ucsb.edu/~almeroth/classes/F04.176A/homework1_good_papers/jay-akkad.html Jay Akkad, The History of Email ]</ref> The [[United States Department of Defense|Department of Defense]] [[DARPA]] desired to have uniformity and interoperability for e-mail and therefore funded efforts to drive towards unified interoperable standards. This led to David Crocker, John Vittal, Kenneth Pogran, and Austin Henderson publishing RFC 733, "Standard for the Format of ARPA Network Text Message" (November 21, 1977), which was apparently not effective. In 1979, a meeting was held at BBN to resolve incompatibility issues. [[Jon Postel]] recounted the meeting in RFC 808, "Summary of Computer Mail Services Meeting Held at BBN on 10 January 1979" (March 1, 1982), which includes an appendix listing the varying e-mail systems at the time. This, in turn, lead to the release of David Crocker's RFC 822, "Standard for the Format of ARPA Internet Text Messages" (August 13, 1982).<ref>[http://www.livinginternet.com/e/ei.htm Email History, How Email was Invented , Living Internet]</ref>
 
The [[జాతీయ సైన్స్ ఫౌండేషన్]] took over operations of the ARPANET and Internet from the Department of Defense, and initiated [[NSFNet]], a new [[backbone]] for the network. A part of the NSFNet AUP forbade commercial traffic.<ref>[http://www.cybertelecom.org/notes/internet_history80s.htm Cybertelecom : Internet History]</ref> In 1988, [[Vint Cerf]] arranged for an interconnection of [[MCI Mail]] with NSFNET on an experimental basis. The following year Compuserve e-mail interconnected with NSFNET. Within a few years the commercial traffic restriction was removed from NSFNETs AUP, and NSFNET was privatized.
 
In the late 1990s, the [[Federal Trade Commission]] grew concerned with fraud transpiring in ఈ-మెయిల్ , and initiated a series of procedures on spam, fraud, and phishing.<ref>[http://www.cybertelecom.org/spam/Spamref.htm Cybertelecom : SPAM Reference]</ref> In 2004, FTC jurisdiction over spam was codified into law in the form of the [[Can Spam Act|CAN SPAM Act.]]<ref>[http://www.cybertelecom.org/spam/canspam.htm Cybertelecom : Can Spam Act]</ref> Several other US Federal Agencies have also exercised jurisdiction including the Department of Justice and the Secret Service.
 
== ఇవీ చూడండి ==
{{portal|Internet|Internet_Kiosk_VTBS.JPG}}
 
=== విస్తరింపులు===
=== Enhancements ===
* [[ఈ-మెయిల్ ఎంక్రిప్షన్]]
* [[HTML ఈ-మెయిల్]]
* [[Google Wave]]
 
=== ఈ-మెయిల్ social issuesసామాజిక సమస్యలు===
{{top}}
* [[Anti-spam techniques (ఈ-మెయిల్)]]
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