Electronic Mail (E-Mail)

Electronic mail, most commonly referred to as email or e-mail since approximately 1993,

is a method of exchanging digital messages from an author to one or more recipients. Modern email operates across the Internet or other computer networks. Some early email systems required that the author and the recipient both be online at the same time, in common with instant messaging. Today's email systems are based on a store-and-forward model. Email servers accept, forward, deliver, and store messages. Neither the users nor their computers are required to be online simultaneously; they need connect only briefly, typically to an email server, for as long as it takes to send or receive messages.

Historically, the term electronic mail was used generically for any electronic document transmission. For example, several writers in the early 1970s used the term to describe fax document transmission. As a result, it is difficult to find the first citation for the use of the term with the more specific meaning it has today.

An Internet email message consists of three components, the message envelope, the message header, and the message body. The message header contains control information, including, minimally, an originator's email address and one or more recipient addresses. Usually descriptive information is also added, such as a subject header field and a message submission date/time stamp.

Originally a text-only (ASCII) communications medium, Internet email was extended to carry, e.g., text in other character sets, multi-media content attachments, a process standardized in RFC 2045 through 2049. Collectively, these RFCs have come to be called Multipurpose Internet Mail Extensions (MIME). Subsequently, the IETF defined an internationalization framework, e.g., Email Address Internationalization (eai), for using unencoded UTF-8 in email.

Electronic mail predates the inception of the Internet and was in fact a crucial tool in creating it,[5] but the history of modern, global Internet email services reaches back to the early ARPANET. Standards for encoding email messages were proposed as early as 1973 (RFC 561). Conversion from ARPANET to the Internet in the early 1980s produced the core of the current services. An email sent in the early 1970s looks quite similar to a basic text message sent on the Internet today.

Email, e-mail or electronic mail is the transmission of messages (emails or email messages) over electronic networks like the internet.

I guess this dry definition is not what you've been looking for. And indeed, it doesn't say or mean much, not to me either. This "transmission of messages" could be anything. But don't let that intimidate or confuse you. Email is as simple and straight forward as letter writing.

Email and Postal Mail

To get a grasp of what email is its best — the terminology indicates it — to think in equivalents of "traditional" postal mail.

The email message - Instead of using a pen to write a letter on paper, you're using your keyboard to type an email message in an email program on your computer.

Sending the email - When the email is finished and has been addressed to the recipient's email address, you don't put a stamp on it and post it but press the Send button in the email program. This makes the email message go on its journey.

Email transport - Like postal services transport letters and parcel, email servers transmit email messages from sender to recipient. Usually, emails are not delivered to the recipient directly, though, but waiting at the "nearest" mail server to be picked up by them.

Fetching new mail - If you've got new mail in your mailbox, you go and fetch it. Similarly, your email program can check for new email messages at your mail server and download them for you to read.

Every day, the citizens of the Internet send each other billions of e-mail messages. If you're online a lot, you yourself may send a dozen or more e-mails each day without even thinking about it. Obviously, e-mail has become an extremely popular communication tool.

Have you ever wondered how e-mail gets from your computer to a friend halfway around the world? What is a POP3 server, and how does it hold your mail? The answers may surprise you, because it turns out that e-mail is an incredibly simple system at its core. In this article, we'll take an in-depth look at e-mail and how it works.

An E-mail Message

According to Darwin Magazine: Prime Movers, the first e-mail message was sent in 1971 by an engineer named Ray Tomlinson. Prior to this, you could only send messages to users on a single machine. Tomlinson's breakthrough was the ability to send messages to other machines on the Internet, using the @ sign to designate the receiving machine.

An e-mail message has always been nothing more than a simple text message -- a piece of text sent to a recipient. In the beginning and even today, e-mail messages tend to be short pieces of text, although the ability to add attachments now makes many messages quite long. Even with attachments, however, e-mail messages continue to be text messages -- we'll see why when we get to the section on attachments.

E-mail Clients

You've probably already received several e-mail messages today. To look at them, you use some sort of e-mail client. Many people use well-known, stand-alone clients like Microsoft Outlook, Outlook Express, Eudora or Pegasus. People who subscribe to free e-mail services like Hotmail or Yahoo use an e-mail client that appears in a Web page. If you're an AOL customer, you use AOL's e-mail reader. No matter which type of client you're using, it generally does four things:

• Shows you a list of all of the messages in your mailbox by displaying the message headers. The header shows you who sent the mail, the subject of the mail and may also show the time and date of the message and the message size.
• Let’s you select a message header and read the body of the e-mail message.
• Let's you create new messages and send them. You type in the e-mail address of the recipient and the subject for the message, and then type the body of the message.
• Let’s you add attachments to messages you send and save the attachments from messages you receive.

Sophisticated e-mail clients may have all sorts of bells and whistles, but at the core, this is all that an e-mail client does.

Spelling

Electronic mail has several English spelling options that occasionally prove cause for vehement disagreement.

E-mail is the most common form in print, and is recommended by some prominent journalistic and technical style guides. According to Corpus of Contemporary American English data, this is the form that appears most frequently in edited, published American English and British English writing.

Email is the most common form used online, and is required by IETF Requests for Comment and working groups and increasingly by style guides. This spelling also appears in most dictionaries.

Mail was the form used in the original RFC. The service is referred to as mail and a single piece of electronic mail is called a message.

Email, capitalizing only the letter M, was common among ARPANET users and the early developers of UNIX, CMS, AppleLink, eWorld, AOL, GEnie, and Hotmail.

Email is a traditional form that has been used in RFCs for the "Author's Address", and is expressly required "for historical reasons".

E-mail is sometimes used, capitalizing the initial letter E as in similar abbreviations like E-piano, E-guitar, A-bomb, H-bomb, and C-section.

There is also some variety in the plural form of the term. In US English email is used as a mass noun (like the term mail for items sent through the postal system), but in British English it is more commonly used as a count noun with the plural emails.

Origin

AUTODIN network provided message service between 1,350 terminals, handling 30 million messages per month, with an average message length of approximately 3,000 characters.

Autodin was supported by 18 large computerized switches, and was connected to the United States General Services Administration Advanced Record System, which provided similar services to roughly 2,500 terminals.

Host-based mail systems

With the introduction of MIT's Compatible Time-Sharing System (CTSS) in 1961 multiple users were able to log into a central system from remote dial-up terminals, and to store and share files on the central disk. Informal methods of using this to pass messages developed and were expanded to create the first system worthy of the name "email":

• 1965 – MIT's CTSS MAIL.
• Other early systems soon had their own email applications:
• 1962 – 1440/1460 Administrative Terminal System
• 1968 – ATS/360
• 1972 – Unix mail program
• 1972 – APL Mailbox by Larry Breed
• 1974 – The PLATO IV Notes on-line message board system was generalized to offer 'personal notes' (email) in August, 1974.
• 1978 – EMAIL at University of Medicine and Dentistry of New Jersey
• 1981 – PROFS by IBM
• 1982 – ALL-IN-1 by Digital Equipment Corporation

Email networks

Soon systems were developed to link compatible mail programs between different organizations’s over dialup modems or leased lines, creating local and global networks.

In 1971 the first ARPANET email was sent, and through RFC 561, RFC 680, RFC 724, and finally 1977's RFC 733, became a standardized working system.

Other, separate networks were also being created including:

• UNIX mail was networked by 1978's uucp, which was also used for USENET newsgroup postings
• IBM mainframe email was linked by BITNET in 1981
• IBM PCs running DOS in 1984 could link with FidoNet for email and shared bulletin board posting

Uses of Email

Flaming

Flaming occurs when a person sends a message with angry or antagonistic content. The

term is derived from the use of the word Incendiary to describe particularly heated email discussions. Flaming is assumed to be more common today because of the ease and impersonality of email 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.

Email bankruptcy

Also known as "email fatigue", email bankruptcy is when a user ignores a large number of email 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 email inbox is being cleared out. Harvard University law professor Lawrence Lessig is credited with coining this term, but he may only have popularized it.

In business

Email was widely accepted by the business community as the first broad electronic communication medium and was the first 'e-revolution' in business communication. Email is very simple to understand and like postal mail, email solves two basic problems of communication: logistics and synchronization.

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 allows the small business user to have multiple users' email IDs with just one email connection.

Pros

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. Email 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 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. Email allows asynchrony: each participant may control their schedule independently.

Cons

Most business workers today spend from one to two hours of their working day on email: reading, ordering, sorting, and’re-contextualizing' fragmented information, and writing email. The use of email is increasing due to increasing levels of globalization – labor division and outsourcing amongst other things. Email 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: Email is a push technology – the sender controls who receives the information. Convenient availability of mailing lists and use of "copy all" can lead to people receiving unwanted or irrelevant information of no use to them.
• Inconsistency: Email 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.
• Liability. Statements made in an email can be deemed legally binding and be used against a party in a court of law.

Despite these disadvantages, email has become the most widely used medium of communication within the business world. In fact, a 2010 study on workplace communication, found that 83% of U.S. knowledge workers felt that email was critical to their success and productivity at work.

Research on email marketing

Research suggests that email marketing can be viewed as useful by consumers if it contains information such as special sales offerings and new product information. Offering interesting hyperlinks or generic information on consumer trends is less useful. This research by Martin et al. (2003) also shows that if consumers find email marketing useful, they are likely to visit a store, thereby overcoming limitations of Internet marketing such as not being able to touch or try on a product.

Problems

Speed of correspondence

Despite its name implying that its use is faster than either postal (physical) mail or telephone calls, correspondence over email often varies incredibly steeply — ranging from communication that is indeed semi-instant (often the fastest when a person is already sitting in front of a computer with their email program open, or when the person has email services automatically set up to speedily check for new messages on their mobile phone) to communication that can quite literally take weeks or even months to garner a response. In the case of the latter, it often proves much more rapid to call the person via telephone or via some other means of audio. Therefore, as a rule, unless one's workplace or social circle already communicates heavily via email in a rapid manner, a person should assume that email runs a perpetual risk of actually being slower as a communication mode than either mobile phone or text messaging communication.

This general rule of thumb is often perplexing to those who use email heavily but whose colleagues and friends do not. Meanwhile, some people, due to exasperation with not getting responses to urgent messages, may eventually decline to use email with any regularity at all, and may be put in the sometimes-awkward position of having to notify their friends and colleagues who do use email regularly, that this is not a good way to reach them.

Attachment size limitation

Email messages may have one or more attachments, i.e., MIME parts intended to provide copies of files. Attachments serve the purpose of delivering binary or text files of unspecified size. In principle there is no technical intrinsic restriction in the InternetMessage Format, SMTP protocol or MIME limiting the size or number of attachments. In practice, however, email service providers implement various limitations on the permissible size of files or the size of an entire message.

Furthermore, due to technical reasons, often a small attachment can increase in size when sent, which can be confusing to senders when trying to assess whether they can or cannot send a file by email, and this can result in their message being rejected.

As larger and larger file sizes are being created and traded, many users are either forced to upload and download their files using an FTP server, or more popularly, use online file sharing facilities or services, usually over web-friendly HTTP, in order to send and receive them.

Information overload

A December 2007 New York Times blog post described information overload as "a $650 Billion Drag on the Economy", 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 email really eliminates the problem of email overload because none helps us prepare replies". GigaOm posted a similar article in September 2010, highlighting research that found 57% of knowledge workers were overwhelmed by the volume of email they received. 

Technology investors reflect similar concerns.

In October 2010, CNN published an article titled "Happy Information Overload Day" that compiled research on email overload from IT companies and productivity experts. According to Basex, the average knowledge worker receives 93 emails a day. Subsequent studies have reported higher numbers. Marsha Egan, an email productivity expert, called email technology both a blessing and a curse in the article. She stated, "Everyone just learns that they have to have it dinging and flashing and open just in case the boss e-mails," she said. "The best gift any group can give each other is to never use e-mail urgently. If you need it within three hours, pick up the phone."

Spamming and computer viruses

The usefulness of email is being threatened by four phenomena: email bombardment, spamming, phishing, and email worms.

Spamming is unsolicited commercial (or bulk) email. Because of the minuscule cost of sending email, spammers can send hundreds of millions of email 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 email each day.

Email worms use email as a way of replicating themselves into vulnerable computers. Although the first email worm affected UNIX computers, the problem is most common today on the Microsoft Windows operating system.

The combination of spam and worm programs results in users receiving a constant drizzle of junk email, which reduces the usefulness of email as a practical tool.

A number of anti-spam techniques mitigate the impact of spam. In the United States, U.S. Congress has also passed a law, the Can Spam Act of 2003, attempting to regulate such email. Australia also has very strict spam laws restricting the sending of spam from an Australian ISP, but its impact has been minimal since most spam comes from regimes that seem reluctant to regulate the sending of spam.

Email spoofing

Email 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.

Email bombing

Email bombing is the intentional sending of large volumes of messages to a target address. The overloading of the target email address can render it unusable and can even cause the mail server to crash.

Privacy concerns

Today it can be important to distinguish between Internet and internal email systems. Internet email may travel and be stored on networks and computers without the sender's or the recipient's control. During the transit time it is possible that third parties read or even modify the content. Internal mail systems, in which the information never leaves the organizational network, may be more secure, although information technology personnel and others whose function may involve monitoring or managing may be accessing the email of other employees.

Email privacy, without some security precautions, can be compromised because:

• Email messages are generally not encrypted.
• Email messages have to go through intermediate computers before reaching their destination, meaning it is relatively easy for others to intercept and read messages.
• Many Internet Service Providers (ISP) store copies of email messages on their mail servers before they are delivered. 
• The backups of these can remain for up to several months on their server, despite deletion from the mailbox.

The "Received:"-fields and other information in the email 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 Networks or the Tor anonymity network can be used to encrypt traffic from the user machine to a safer network while GPG, PGP, SMEmail, 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 agents do not protect logins and passwords, making them easy to intercept by an attacker. Encrypted authentication schemes such as SASL prevent this.

Finally, attached files share many of the same hazards as those found in peer-to-peer filesharing. Attached files may contain Trojans or viruses.

Tracking of sent mail

The original SMTP mail service provides limited mechanisms for tracking a transmitted message, and none for verifying that it has been delivered or read. It requires that each mail server must either deliver it onward or return a failure notice (bounce message), but both software bugs and system failures can cause messages to be lost. To remedy this, the IETF introduced Delivery Status Notifications (delivery receipts) and Message Disposition Notifications (return receipts); however, these are not universally deployed in production. (A complete Message Tracking mechanism was also defined, but it never gained traction; see RFCs 3885 through 3888.)

Many ISPs now deliberately disable non-delivery reports (NDRs) and delivery receipts due to the activities of spammers:

• Delivery Reports can be used to verify whether an address exists and so is available to be spammed

If the spammer uses a forged sender email address (email spoofing), then the innocent email address that was used can be flooded with NDRs from the many invalid email addresses the spammer may have attempted to mail. These NDRs then constitute spam from the ISP to the innocent user.

There are a number of systems that allow the sender to see if messages have been opened. The receiver could also let the sender know that the emails have been opened through an "Okay" button. A check sign can appear in the sender's screen when the receiver's "Okay" button is pressed.

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