This seminar describes the basic aspects of the functionality of electronic mail

1. Presented by:
Deeptanu Datta
Roll No. 1811EE05
A
PRESENTATION
on
Electronic Mail
Guided by :
Dr. Sudhan Majhi
Associate Professor
Department of Electrical
Engineering
IIT Patna
Indian Institute of Technology Patna

2. Outlines
• Introduction
• Format of email
• Email address
• Components of email
• Architecture of email
• User Agent
• Message Transfer Agent
• Message Access Agent
• Post Office Protocol
• Internet Mail Access Protocol
• Introduction to MIME

3. Introduction
• Electronic Mail is a method to exchange
messages between people by electronic
devices across the Internet
• Invented by US scientist Ray Tomlinson in 1960
• Earlier email used to operate in instant messaging
mode – both users need to be online simultaneously
• Modern email operates in store and forward mode
– Email servers accepts, forwards, deliver, and store messages
– Users need not to remain online simultaneously

4. Format of email

5. Email Address
•Local part defines user mailbox, where all mails are
stored
•Domain name comes from DNS database
•Domain Name System is a network system that
translates names into IP addresses

6. Three Components of Email
User Agent (UA)
Message Transfer Agent (MTA)
Message Access Agent (MAA)

7. Architecture of Email
Sender Receiver
Mail Server Mail Server
MAA
Client

8. User Agent

9. Message Transfer Agent
• PUSH protocol – pushes message from client to server
• Simple Mail Transfer Protocol defines MTA client
and MTA server in the Internet
• SMTP is used two times – between the sender
and the sender’s mail server and between the
two mail servers
• SMTP defines how commands and responses
must be sent back and forth
• Commands are from MTA client to MTA server
• Responses are from MTA server to MTA client

10. Message Access Agent
• PULL protocol – pulls message from server to client
• Post Office (v3) Protocol and Internet Mail
Access(v4) Protocol defines MAA client and
server in the Internet
• MAA is involved only once – between the
receiver’s mail server and the receiver
• POP is a simple protocol with limited
functionality
• IMAP is similar to POP, but it has more
features and is more complex

11. Post Office Protocol
•Client POP is in receiver’s
computer
•Server POP is in mail server
•Two modes – delete and
keep
•In delete mode, mail is
deleted from mailbox after
each retrieval
•In keep mode, mail remains
in mailbox after retrieval

12. Internet Mail Access Protocol
• User can check the email header before downloading
• User can search the contents of the email for a
specific string of characters before downloading
• User can partially download an email with
multimedia contents if bandwidth is limited
• User can create, delete, or rename mailboxes
on the mail server
• Hierarchy of mailboxes can also be created in
a folder for email storage

13. Multipurpose Internet Mail Extension
•MIME allows non-ASCII data to be sent through email
•Converts non-ASCII data to ASCII data and delivers it to client MTA at the sender side
•Converts ASCII data to non-ASCII data after receiving it from server MTA at the receiver side

14. THANK YOU