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8/6/2019 08-Email and Chat
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Advanced Network Services Topic 8 Email and Chat
Email and Chat
17:22 ( 1 of 35)
GROUP NAME:-YASER PATEL
PATEL HANIF
PRAFUL
JESHAN
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Advanced Network Services Topic 8 Email and Chat
Many faces of Messagingy DeliveringDatay texty binaryy graphicy digitized videoy audio
y Between human users / computer systemsy Messaging types
y Emaily Directemaily Web based Email
y Chaty IRCy Instant messagingy Web based chat
y Short Message Service (SMS)
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Advanced Network Services Topic 8 Email and Chat
MHS (Message Handling Service)
Components
MTS
MTA
MTAMTA
UA
UA
UA
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Advanced Network Services Topic 8 Email and Chat
MHS Layout
UA UA
P2 (MIME,MAPI)
Video, data, audio, etc.
P3(IMAP,POP3,
SMTP)
P3
MTA MTA MTA MTA
MTS
P1 P1 P1
(SMTP)
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Advanced Network Services Topic 8 Email and Chat
MHS Componentsy User Agent (UA)
y Program, with which human users read, create and
managee-maily Reads and writes messages using a P3 protocol
y Encodes and decodes messages using a P2 protocol
y Mail Transport Agent (MTA)y Transfers messages between computers
y Store and forward (non-real-time)
y Uses a P1 protocol
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Advanced Network Services Topic 8 Email and Chat
Practical implementation of MHS protocols
y P1 movement of messagesy SMTP Simple Mail Transfer Protocol
yP2 coding and decoding messagesy MIME Multipurpose Internet Mail Extension
y MAPI - Messaging Application Programming Interface
y P3 reading and sending messages
y SMTP to sendy POP (Post Office Protocol) toread
y IMAP (Internet Message Access Protocol) toread
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Advanced Network Services Topic 8 Email and Chat
Email in a picture
SMTP
POP or
IMAP
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Advanced Network Services Topic 8 Email and Chat
Web maily Mail where the UA is in a browser
y Where is the sending MTA?
y All therest is the samey UA- local MTA communication
y Not using SMTP, POP, IMAP
y Internal to the Web provider
y In the filesystem?y Proprietaryprotocols?
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Advanced Network Services Topic 8 Email and Chat
Format of messagesy RFC 822: STANDARD FOR THE FORMAT OF
ARPA INTERNET TEXT MESSAGESy Published in 1982
y Defines a format for text messages that are sentusing emaily Contains headers like From, To, Subject, Datey Lines no longer than 1000 chary
Message body- plain US-ASCII text (7 bits!)y Message header lines - plain US-ASCII texty Limit on message length
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Advanced Network Services Topic 8 Email and Chat
Email headery The mail data consists of a header and a message body,
separated bya blank line.
y the header includes colon terminated fields such as:y To:y From:
y Subject:
y Date:
y Received:
y added to by intermediary MTAs. It is a form of postmark
y Cc:
y My own header:
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Advanced Network Services Topic 8 Email and Chat
SMTP commandsy $telnet students.ballarat.edu.au 25y HELO y MAIL From:
y RCPTTo:y Datay Subject:Test emaily Hello there y .y 250 Ok: queued as F28B08603y Quity 221 Bye
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Advanced Network Services Topic 8 Email and Chat
POP and IMAP
y Both are standards forreceiving email from aremote machiney Read email from mail file created byMTA
y POP (Post Office Protocol)y You can get, list, and delete mail.y Email downloaded gets stored on the local machine
y IMAP (Internet Message Access Protocol)y Quicklydownload header information and then readonlythe messagesyou want toread.y Email can be stored online in different foldersy Offline mode available
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Advanced Network Services Topic 8 Email and Chat
POP-3 Commands
y USER- specifyusername
y PASS - specifypassword
y STAT- get mailbox status
LIST- get a list of messages and sizes
y RETR- retrieve a message
y DELE - mark a message for deletion from the mailbox
y NOOP- send back positivereply
y RSET- reset. All deletion marks are unmarked
y QUIT- remove marked messages and close the (TCP)
connection
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Advanced Network Services Topic 8 Email and Chat
S/MIME
(Secure/Multipurpose Internet Mail Extensions)
y Verysimilar to PGP
y Likelytoemerge as industrystandard for commercial
use (PGP for personal)y Message signature
y Messageencryption
y Based on RSA
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Advanced Network Services Topic 8 Email and Chat
What does S/MIME give us?y Secrecy Onlyintended recipient can read the
message. (A thick envelope and trustworthycouriers.)
y
Authentication Recipient knows the message camefrom the apparent sender. (An ink signature thatyourecognize.)
y Integrity Recipient knows the message was notchanged en route. (Un-erasable ink in a letter.)
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Advanced Network Services Topic 8 Email and Chat
sendmail Unix MTAy Backboneof Internet email
y Open Source full function MTA
y On Adios disky Standard Linux service
y service sendmail start
y sendmail server listens for connections
y sendmail client passes messages on
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Advanced Network Services Topic 8 Email and Chat
sendmail and DNSy MTA uses DNS to check validityof sender, receiveretc
y Lab requiresyourown DNS server
y Download and extract DNS filesy Usenamed g u namedto start server
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Advanced Network Services Topic 8 Email and Chat
sendmail securityy Open relay
y Allows anyclient to send email anywhere
y Great for spammers!y Bydefault disabled
y Remote access
y Listening to a real IP/port
y Bydefault onlylocalhost
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Advanced Network Services Topic 8 Email and Chat
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Advanced Network Services Topic 8 Email and Chat
New Account - Outlook Express
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Advanced Network Services Topic 8 Email and Chat
New Account - Outlook Express
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Advanced Network Services Topic 8 Email and Chat
New Account - Outlook Express
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Advanced Network Services Topic 8 Email and Chat
New Account - Outlook Express
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Advanced Network Services Topic 8 Email and Chat
New Account - Outlook Express
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Advanced Network Services Topic 8 Email and Chat
MicrosoftO
utlookEx
press
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Advanced Network Services Topic 8 Email and Chat
Send and receive e-mail
To send an e-mail message: Press the New Mail button on the Outlook Express toolbar Type in thee-mail addresses of therecipient Typeyour subject matter Typeyour message and then click the Send button
Toretrieve mail that has been sent toyou: Click the Send/Recv button on the toolbar Outlook Express will contactyoure-mail server and downloadyour
e-mail messages
Toreplyto a message: Click the Replybutton Therecipient address and the subject matter are automaticallyfilled
in Whenyou have completed typingyourreply, click the Send button
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Advanced Network Services Topic 8 Email and Chat
The Outlook Express
New Message dialog box
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Advanced Network Services Topic 8 Email and Chat
Reply to an e
-mail message
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Advanced Network Services Topic 8 Email and Chat
Adding contacts to the
Address Book You can use the Address Book to keep track of
all the people and organizations with which
you correspond electronically. You not onlycan store thee-mail addresses foryour contacts, but also all otherrelatedinformation.
Click the Addresses button on the toolbar toopen the Address Book, and then select NewContact from the New button on the toolbar.
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Advanced Network Services Topic 8 Email and Chat
Adding contacts to the
Address Book
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Advanced Network Services Topic 8 Email and Chat
Advantages of Outlook Express
and other email programsy There are several advantages of Outlook Express and other
email management software such asWindows MailVista,Windows Live Mail, Outlook, Thunderbird, Zimbraetc.
y Availability of email even without an internetconnection: Ifyou've been using web based emailaccounts such as Hotmail, Gmail or Yahoo! Mail,you knowthat an active internet connection is required to login toyouronline account and access messages. With Outlook
Express, the program will automaticallyconnect toyouraccount,download email and store them onyour computer.Since now the messages areonyour local machine theyareavailable toyou even without an internet connection.
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Advanced Network Services Topic 8 Email and Chat
Advantages of Outlook Express
and other email programsy Save time by downloading email from various accounts: This point applies
to thosewho have multipleemail accounts. You don't need to waste time inchecking each email account separately. Multiple accounts can be set up inOutlook Expresswhich means email from all these accounts will bedownloaded together at one place - your computer. You can also use filters
and Outlook Express messagerules to segregateemail messages as theyarriveatyour system. Forexample, all incoming Gmail messages can be diverted toone folder while those from Hotmail to another. You can similarlyisolateemailsbased on sender, file size, whether theyhave attachments etc.
y Acopy of your emails in on your computer: Probablythe most importantadvantage of using Outlook Express and otheremail management software isthe abilityto store a copyof allyouremail onyour computer. Soeven ifyou
accidentlydelete an important message fromyour serveror if (God forbid)youraccount is hacked or is inaccessible,you knowyou can retrieve the messagesfromyour system. Also, to playit reallysafe,you can takeregular backups ofOutlook Express.
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Advanced Network Services Topic 8 Email and Chat
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Advanced Network Services Topic 8 Email and Chat
What Is Chat?
y
Real tim
eco
mmunicatio
nover
the
Inter
net.
y Synchronousy Email is asynchronous
y Types of chaty PrivateChaty Public Chats
yApproachesof chaty Internet RelayChat (IRC)y Instant Messaging Softwarey Web-Based Chat
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Advanced Network Services Topic 8 Email and Chat
Internet Relay Chat
y Based on UNIXTalk
y IRC uses a client-server network model: IRC serversare connected through the internet to form an IRCnetwork.
y Individual chat participants use IRC client softwareand connect to the servers in the network.
y IRC uses a simple text-based protocol
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Advanced Network Services Topic 8 Email and Chat
Instant Messaging Softwarey Instant messaging software lets two users chat in real
timeover the Internet.
y
Usuallybetween people who know each othery Tools that letyou identifyyour friends and alertyou
whenyour friends areonline.
y Various protocols
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Advanced Network Services Topic 8 Email and Chat
Instant Messaging Softwarey Instant messaging software programs:
y Proprietaryprotocols
y
ICQy AOL Instant Messenger
y Windows Messenger
y Yahoo! Messenger
y Multi protocol
y Pidgin (formerlyGAIM)
y Trillian
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Advanced Network Services Topic 8 Email and Chat
Web-based ChatyWeb-based chat is even more convenient than
Windows-based chat programs. Users do not need
to install anyprogram. Theyreach a chat site, login and begin to chat.
y There are two forms of web-based chat rooms:html version and Java Applet version. The html
chat rooms are programmed in html (hypertextmark-up language) and the Java Applet charroomsare programmed in Java language.
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Advanced Network Services Topic 8 Email and Chat
Web-Based Chat Sitesy Most Web-based chat sites prohibit spam
messages, the useof automated programs, profane
and vulgar language, and threats to individuals.y Most sites requireyou toregister beforeusing their
chat rooms.
yAlthough Web sites that provide chat rooms have
rules of appropriate conduct,you might encounterconversations taking place that areoffensive toyou.
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Advanced Network Services Topic 8 Email and Chat
Voice Chaty Voice Chat is the chat using voice.y Onceyou connect to a voice char server,your can
talk toother people in the same chat room or listento their talking.
y The sound qualitydepends on several factors suchas: speed of the Internet connection, Internettraffic and numberof participants in the same chat
room.y Voice chat rooms mayhave a limit of numbers of
participants.
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Advanced Network Services Topic 8 Email and Chat
THANK YOU