This document discusses email and how it works. It explains that email allows sending messages with text, voice, video or graphics to one or more recipients. It describes how emails have an envelope containing sender/receiver addresses and a message body. Addresses use a local part and domain name format. Email uses user agents to compose, read, reply and forward messages, and handle mailboxes. MIME allows non-ASCII data to be sent through SMTP. Email transfer occurs through mail transfer agents, requiring a client MTA to send and server MTA to receive. Delivery has three stages: connection establishment, message transfer, and connection termination.

1. Presented By
Baljit Saini

2. E-mail is used for sending a single message
that includes text,voice,video or graphics to
one or more recipients
Sending E-mail: To send e-mail user creates a
mail which includes envelope and a message.
 envelope contains sender address, receiver
address and other information
 Message contains header and the body. Body
of the message contains the actual
information to be read by the recipient

3. Addresses: to deliver a mail handling ystem
must use an addressing system with unique
addresses. Addressing system used by SMTP
consist of two parts
Local part @domain name

4.  User Agent
 Mail Transfer Agent

5.  User agent is a software package that
compose,reads,replies to and forward
messages. It also handles mail boxes
User Agent
Composing
Message
Reading
Message
Replying to
message
Forwarding
Message
Handling
mailboxes

6.  Command Driven
 GUI based

7.  SMTP can send messages only in 7bit ASCII format
 It cannot be used for languages that are not
supported by 7 bit ASCII characters
 MIME is a supplementary protocol that allows non
ASCII data to be sent through SMTP
USER USER
Non ASCII code Non ASCII Code
ASCII code ASCII Code
MIME
SMTP SMTP
MIME

8.  E-mail transfer is done through mail transfer
agent. To send e-mail system must have
client MTA and to receive e-mail system must
have server MTA
Commands
Response
MTA Client MTA Server

9.  Connection Establishment
 Message Transfer
 Connection Termination

10. Delivery of e-mail from the sender to the
receiver consist of three stages
 Stage 1
 Stage2
 Stage 3

11. First Second Stage Third
desktop Mail
Server
internet Mail
Server
desktop