11-01-2014, 01:22 PM
Electronic mail
Electronic mail.ppt (Size: 2.61 MB / Downloads: 26)
WHAT IS MAIL
Electronic mail, often abbreviated as E-mail, is a method of exchanging digital messages, designed primarily for human use.
E-mail systems are based on a store & forward model in which E-mail server systems accept, forward, deliver and store messages on behalf of users, who only need to connect to the e-mail infrastructure.
STRUCTURE OF MAIL
An electronic mail message consists of two components
Message header, The message header contains control information, including an originator's email address and one or more recipient addresses. Usually additional information is added, such as a subject header field
Message body, which is the email's content.
MAIL ADDRESS
To deliver mail ,a system must use an addressing system with unique addresses
Address consist two parts :
Local part
Domain name
USER AGENT
The first component of E-mail is user agent(UA).
It provide the services to user to make the process of sending & receiving a message easier.
A UA is a software package(Program) that composes,reads,replies to and forwards messages.
It also handles the Mailboxes.
Two types of user agents – (i) Command Driven
(ii)GUI-based(Graphical user interface)
These are separated by @ sign.
SUMMARY
The architecture of email have four senarios.Out of these fourth senario is the most common in exchange of email.
UA prepares the messages, creates the envelopes, and puts the message in the envelope.
Mail address is like localpart@domainname.
Multipurpose Internet Mail Extensions (MIME) allows the transfer of multimedia messages.MIME is the supplementary protocol that allows non-ASCII data to be sent through email.