School of Electronics and Telecommunications
1/25
Presented by: Pham Van Chi
Bui Thi The Ha
Electronic Mail: SMTP
School of Electronics and Telecommunications
2/25
OBJECTIVES:
OBJECTIVES:

To explain the architecture of electronic mail using four scenarios.

To explain the user agent (UA)

Transfer Protocol (SMTP) as the formal protocol that handles MTA.

To explain e-mail transfer phases.
School of Electronics and Telecommunications
3/25
Explain the architecture of electronic mail
To explain the architecture of email, we give four scenarios
To explain the architecture of email, we give four scenarios

Scenarior 1

Scenarior 2

Scenarior 3

Scenarior 4
School of Electronics and Telecommunications

1
2
3
4
5
6
7
School of Electronics and Telecommunications
9/25
When the sender is connected to the mail
server via a LAN or a WAN, we
need two UAs and two pairs of MTAs
(client and server).
Note:
Note:
School of Electronics and Telecommunications
10/25
Figure 4 Fourth scenario
1
2
3
4
5
6
8
9
School of Electronics and Telecommunications
11/25
When both sender and receiver are
connected to the mail server via a LAN or a

- g i mail, h th ng ph i có client MTAĐể ử ệ ố ả
-
nh n mail. H th ng ph i có server MTAĐể ậ ệ ố ả
-
Giao th c nh ngh a MTA client và server trên Internet ứ đị ĩ
c g i là SMTP (Simple Mail Transfer Protocol)đượ ọ
-
Scenario 4 là tr ng h p th ng g p nh tườ ợ ườ ặ ấ
-
Hình 7 th hi n ph m vi s d ng giao th c SMTP trong ể ệ ạ ử ụ ứ
scenario này
School of Electronics and Telecommunications
16/25
Figure 7 SMTP range
School of Electronics and Telecommunications
17/25
Figure 8 Commands and responses
•
command/response interaction
– commands: ASCII text
– response: status code and phrase
•
messages must be in 7-bit ASCII
•
Uses CRLF.CRLF to determine end of message
School of Electronics and Telecommunications
18/25
School of Electronics and Telecommunications
19/25
School of Electronics and Telecommunications

===================== Envelope ===================
MAIL FROM: [email protected]
250 [email protected] Address Okay (Server gives a positive
response)
RCPT TO: [email protected]
250 [email protected] Address Okay
=================== Header and Body ==================
DATA (type this command to start input data)
354 Please start mail input
From:Gates <[email protected]>
To:[email protected]
Date:Sat Jan 5,2008 9:45 PM
Subject:Test to send fake email
School of Electronics and Telecommunications
24/25
Figure 11 SMTP, Pop3 and IMAP4
School of Electronics and Telecommunications
25/25
Any