Group 5.

Overview. WHAT IS E-MAIL . DIFFERENT E-MAIL PROVIDERS. WHAT MAKES UP AN E-MAIL. DIFFERENT ARCHITECTURAL MODELS. HOW E-MAIL REALLY TRAVEL. BOUNCING OF E-MAIL. THREATS TO E-MAIL. OVERCOMING THREATS. CONCLUSION.

Meaning Electronic mail, often abbreviated as email or e-

mail. Email – an electronic message transmitted over a

network from one user to another. Can be as simple as a few lines of text, or include

attachments such as pictures or documents. It is the method of exchanging digital messages

between two or more systems. E-mail systems are based on a store-and-forward

model. In which e-mail computer server systems accept,

forward, deliver and store messages on behalf of user.

History The first email systems were developed at SCD

and MIT in 1965. Incompatible with each other, each system was designed to facilitate message delivery between users on a single machine.

Ray Tomlinson invented email

back in 1971 – essentially fostering global business communication.

It is the easy & cheapest comm.

Definition

Electronic mail (or E-mail ) can be defined as ‘the transformation of computer- stored messages by using telecommunications”

Advantages of E mail

Screening information Bringing Work on the Road Sending Messages to Greet Managing E mail is easy and fast Email is easy to filter E-mails are delivered uninterruptedly

Disadvantages of E-mail

E-Mail Overload Time consuming E-mail and Excuse Infecting your computer with a virus Ignorance

Now a days there many e-mail providers.

Gmail.

Yahoo mail.

Rediff mail.

Hotmail.

Email Providers

How to Sign Up for a Gmail Email Account

1. Go to www.gmail.com

2. Click on “Sign Up for Gmail”

3. Fill in the Registration Form

Create user ID

Cont….Should I provide accurate person information or is it OK to lie?

Unique login name

Password registration boxes and password strength

Security question

Answer to the security question

Description of Google’s Web History

Cont….Email address for authenticating account

Location of person creating an account

Word verification

Terms of Service policy and links to other user policies

Button for creating Gmail account

Sending and Receiving Email

Three Exercises

1. Signing in (“Logging In”) to Gmail

2. Sending a message to your class partner

3. Reading new messages in your “Inbox”

Sending and Receiving Email

Exercise 1: Signing In

1. Go to www.gmail.com 2. Type in your username

and password3. Click on the ‘sign in’

button

Sending and Receiving Email

Exercise 2: Sending an EmailTo: Type full email address of your class partner

Subject: Type a title for your message

Message: Type your message in this box

Send: Used to send emails

Sending and Receiving Email

Confirmation message:

Confirmation message and link to sent message

Sending and Receiving Email

Checking for New Email MessagesThe number of new messages in your account appears beside the Inbox link.Main Menu

Sending and Receiving Email

The Inbox

Messages already opened

Un-read message in bold font

Sending and Receiving Email

Your Messages

TitleSender Date

Double click on a subject to read a message

Managing your Messages

Replying to a Message

“Replying” to a message sends it back to the person who sent it to you.

Exercise: View the message from your partner Click on the “Reply Button” Type in a Reply Click on Send

WHAT MAKES UP AN E-MAIL.Internet e-mail messages consist of two major

sections HeaderHeader

Structured into fields such as summary, sender(from), receiver(to), subject, date , cc ,Bcc, reply, message-id about the e-mail.

BodyBodyThe message itself as unstructured text; sometimes containing a signature block at the end. This is exactly the same as the body of a regular letter.

DIFFERENT ARCHITECTURAL MODELS. Different Architectural Models exist for

constructing computer systems. Some models include

Peer-Peer

Pipe and Filter

Implicit Invocation

Client-Server

Provided Interface

ClientRequired Interface

Provided Interface

ClientRequired Interface

Provided Interface

ClientRequired Interface

Provided Interface

ClientRequired Interface

Provided Interface

ClientRequired Interface

Provided Interface

ClientRequired Interface

Provided Interface

ServerRequired Interface

Provided Interface

ServerRequired Interface

Provided Interface

ClientRequired Interface

Provided Interface

ClientRequired Interface

Provided Interface

ClientRequired Interface

Provided Interface

ClientRequired Interface

Provided Interface

ClientRequired Interface

Provided Interface

ClientRequired Interface

Provided Interface

ServerRequired Interface

Provided Interface

ServerRequired Interface

DIFFERENT ARCHITECTURAL MODELS. The model that works best for email is the

Client-Server model.

Clients carry out user interactions with the email server.

An email client is an email program such as Outlook Express, for sending, receiving and organizing your email messages.

Email servers are used to process, store and send, and receive email messages. There are different types of email servers, such as POP 3, SMTP and IMAP servers. The most popular email servers are POP 3 (incoming mail servers for your incoming mail) and SMTP (outgoing mail servers for your outgoing mail).

Step A: Sender creates and sends an email The originating sender creates an The originating sender creates an

email in their Mail User Agent (MUA) email in their Mail User Agent (MUA) and clicks 'Send‘.and clicks 'Send‘.

Step B: Sender's MDA/MTA routes the email The sender's MUA transfers the email The sender's MUA transfers the email

to a Mail Delivery Agent (MDA).to a Mail Delivery Agent (MDA). Frequently, the sender’s MTA also Frequently, the sender’s MTA also handles the responsibilities of an MDA. handles the responsibilities of an MDA. The MDA/MTA accepts the email, then The MDA/MTA accepts the email, then routes it to local mailboxes.routes it to local mailboxes.

HOW E-MAIL REALLY WORKS

Step C: Network Cloud

The network cloud may encompass a multitude The network cloud may encompass a multitude of mail servers, DNS servers, routers and other of mail servers, DNS servers, routers and other devices and services too numerous to mention.devices and services too numerous to mention.

These devices may be protected by firewalls, These devices may be protected by firewalls, spam filters and malware detection software spam filters and malware detection software that may bounce or even delete an email. that may bounce or even delete an email.

Step D: Email Queue

So it enters an email queue with other o it enters an email queue with other outgoing email messages.outgoing email messages.

Step E: MTA to MTA Transfer

When transferring an email, the sending MTA When transferring an email, the sending MTA handles all aspects of mail delivery until the handles all aspects of mail delivery until the message has been either accepted or rejected by message has been either accepted or rejected by the receiving MTA.the receiving MTA.

Step F: Firewalls, Spam and Virus Filters

An email encountering a firewall may be tested by An email encountering a firewall may be tested by spam and virus filters before it is allowed to pass spam and virus filters before it is allowed to pass inside the firewall. If the message contains inside the firewall. If the message contains malware, the file is usually quarantined and the malware, the file is usually quarantined and the sender is notified. If the message is identified as sender is notified. If the message is identified as spam, it will probably be deleted without notifying spam, it will probably be deleted without notifying the sender.the sender.

BOUNCING OF E-MAIL.Due to the following reasons e-mail will bounce. Mailbox Not Found

Invalid mailbox

Mailbox unavailable

Mailbox full

Host unknown.

A sending MTA can encounter two general kinds of problems transferring an email: Transient or Permanent failures.

Transient failuresIf a transient error occurs, the MTA will hang onto the message, periodically retrying the delivery until it either succeeds or fails, or until the MTA decides that the transient issue is really a permanent condition.

Permanent failuresIf the MTA cannot deliver the message (it has received a fatal error message or failed to complete the transfer after repeated attempts), it bounces the message back to the sender.

THREATS TO E-MAIL E-mail spoofing

Occurs when the header information of an email is altered to make the message appear to come from a known or trusted source.

E-mail bombing

Is the intentional sending of large volumes of messages to a target address. The overloading of the target email address can render it unusable and can even cause the mail server to crash.

OVERCOMING THREATS E-mail messages have to go through

intermediate computers before reaching their destination.

Many Internet Service Providers (ISP) store copies of e-mail messages on their mail servers before they are delivered.

Using encryption techniques.

CONCLUSION There are many uses of e-mail in our daily life.

We should not misuse the e-mail for illegal activities.

We should have our own moral values.

Reference Google

Wikipedia

Team Members

Sonu K Sebastian Sajith P.S Sam Scaria Scaria Joseph Sonia Sebu Surayya

Shruthi.S. Murali Shipla Tony Xavier Thambu John Swathi Raj Roy Thomas

Thank You.