How email works
Email is Electronic Mail. This is mail sent directly from one computer to another, electronically.
This method of communication is similar to the fax, in that it is a way of transmitting written data. With email, however, the document is not a paper one; it has been created on a computer.
An email is sent from the source computer to the receiving computer, using the telephone lines as the transmission method.
- What actually happens, is the email is sent from the source computer to a holding computer known as a mail server.
- The computer at the receiving end is alerted to the fact that an email has arrived.
- The mail server releases the email to the receiving computer; once again, telephone lines send the email.
- The problem with using standard telephone lines is the speed of transmission. The present average transmission speed is 56,600 bits per second. This translates to about 5000 bytes per second, which is rather slow. Big graphics of a megabyte in size can take at least ten minutes to receive.
Follow the process of sending an email on this video: How web-based email works.
A standard email contains only text, which means that, unlike the fax, graphics cannot be included. Files of any kind can be attached and sent with an email, however, so graphics can be sent in this way.
The major problem with adding graphic files to an email is the method of transmitting them. If the attached file is large, it can take ages for it to be downloaded by the receiver, which is time-wasting and expensive.
The alternative to sending email from computer to computer is to use the computer as a fax machine. Drawbacks of this are that the faxed text cannot be used in a word processor, nor can graphics be effectively used in graphics software.
Email does not have to be part of Internet use, although most Internet accounts have email facilities as part of their function. There are a number of email-only services, but these are becoming rarer, as Internet access becomes integrated with email use.
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