EmailShort for electronic mail, e-mail or email is information stored on a computer that is exchanged between two users over telecommunications. More plainly, e-mail is a message that may contain text, files, images, or other attachments sent through a network to a specified individual or group of individuals. The first e-mail was sent by Ray Tomlinson in 1971. By 1996, more electronic mail was being sent than postal mail.

E-mail address breakdown


  • The first portion all e-mail addresses, the part before the @ symbol, contains the alias, user, group, or department of a company. In our above example support is the Technical Support department at Computer Hope.
  • Next, the @ (at sign) is used as a divider in the e-mail address; it is required for all SMTP e-mail addresses since the first message was sent by Ray Tomlinson.
  • Finally, computerhope.com is the domain name to which the user belongs.

How to send and receive e-mail

E-mail Program

To send and receive e-mail messages, you can use an e-mail program, also known as an e-mail client, such as Microsoft Outlook or Mozilla Thunderbird. When using an e-mail client, you must have a server that stores and delivers your messages, which is provided by your ISP or in some cases, another company. An e-mail client needs to connect to a server to download new e-mail, whereas email stored online (see next section) updates automatically when you visit the site.

E-mail Online

An alternative way of sending and receiving e-mail (and the more popular solution for most people) is an online e-mail service or webmail. Examples include Hotmail (now Outlook.com), Gmail, and Yahoo Mail. Many of the online e-mail services, including the ones we just mentioned, are free or have a free account option.

Writing an e-mail

When writing an e-mail message, it should look something like the example window below. As you can see, several fields are required when sending an e-mail:

  • The To field is where you type the e-mail address of the person who is the recipient of your message.
  • The From field should contain your e-mail address.
  • If you are replying to a message, the To and From fields are automatically filled out; if it's a new message, you'll need to enter them manually.
  • The CC or Carbon Copy field allows you to send a copy of the message to another e-mail address, but is not mandatory.
  • The Subject Line, although not required, should consist of a few words describing the e-mail's contents.
  • Finally, the Message Body is the location you type your main message. It often contains your signature at the bottom; similar to a hand-written letter.

Writing an e-mail message

What makes a valid e-mail address?

There are several rules that an e-mail address must follow to be valid:

  • As mentioned earlier, an e-mail must have a username followed by an @ (at sign) which is followed by the domain name with a domain suffix.
  • The username cannot be longer than 64 characters long and the domain name cannot be longer than 254 characters.
  • There should be only one @ sign in an e-mail address.
  • The space and special characters: ( ) , : ; < > \ [ ] are allowed. Occasionally, a space, backslash, and quotation mark work but must be preceded with a forward slash. Although valid, some e-mail providers do not allow these characters.
  • The username and e-mail addresses as a whole cannot begin or end with a period.
  • The e-mail must not have two or more consecutive periods.

Related pages

Also see: Attachment, BCC, Bounce, Chain mail, Distribution list, E-mail bomb, ESP, Exchange, FNEA, Graymail, Header, Inbox, Internet terms, Joe Job, Junk mail folder, Mail exploder, Mail list, Mail merge, Mailbox, MAPI, Message body, MIME, Network terms, Newsletter, Outbox, Phishing, Postmaster, Push e-mail, Re:, Return address, Signature, SMTP, Snail mail, Spam, Subject, Thunderbird, Uuencode, X.400