Electronic mail. !! Task - Assignment!!

(1)

Electronic

mail

2

!! Task - Assignment !!

You can learn about e-mail online through the Internet from

http://www.bbc.co.uk/webwise/course/coursemenu.shtml You can learn about e-mail

online through the Internet from

http://www.bbc.co.uk/webwise/course/coursemenu.shtml

(2)

***-E-mail:

summary

The following gives an overview of electronic mail: • What it is

• Using e-mail through the WWW

• Using e-mail with a dedicated e-mail client software • …

4

E-mail:

prerequisites

Before using e-mail, you should ideally have some knowledge and skills related to

• computer hardware • computer software • the Internet

• the WWW ****

(3)

E-mail:

general description

Electronic mail allows network users to send messages to each other by computer. The process is like the postal system in some ways, but in the case of electronic mail, the mail agent is a computer program

»the address for sending is the address of an electronic mailbox

»the message is given to the mail system electronically, not on paper

»the transport system is the data communication network

6

E-mail

using central, isolated systems

E-mail computer E-mail computer 1 A 2 B Send

Send ReadRead

(4)

?? Question ??

Which problems would be associated with the use of simple, isolated,

CENTRAL systems and services for e-mail ?

Which problems would be associated with the use of simple, isolated,

CENTRAL systems and services for e-mail ?

8

E-mail using central, isolated systems:

problems

In the case of isolated, central systems, there would be problems:

»Message senders must have accounts with various e-mail services to address various persons,

and analogously,

persons who want to receive messages must have accounts with various e-mail services used by the various senders. »As one of the consequences, each user should connect with

various systems to check if e-mail has arrived in their various mailboxes.

(5)

**--E-mail:

gateways link various systems

Gateways solve the problems associated with isolated systems by linking these with each other.

10

E-mail using

linked systems

E-mail computer I E-mail computer I 1 A 2 B E-mail computer II E-mail computer II Send _Read ****

(6)

E-mail:

examples of global systems

• Systems with 1 e-mail computer systems »CompuServe (in US)

»Hotmail (in US) »Yahoo Mail…

• Global, linked network systems »UUCP network »FidoNet... »X-400 network »Internet SMTP 12

E-mail:

getting started

To start, you need: • a networked computer • a mail system (software) • a personal mailbox for you • a little know-how

• e-mail addresses, if you want to send messages • ...

(7)

E-mail

in the Internet

One of the most interesting features of the Internet is that virtually every personal computer, minicomputer and mainframe can connect to it in one fashion or another. There are many operating systems in use on the Internet. Nearly every operating system has its own e-mail style. To overcome the mess of competing “standards”, the Internet has adopted a particular format for e-mail. Based on the RFC (Request for Comments) 822, it is called RFC 822-compliant e-mail.

14

E-mail: transfer protocols

in the Internet

**--Sending server computer used by Y Receiving server computer B used by X Client microcomputer used by X

(with client software = user agent) SMTP

Receiving messages, using POP or IMAP Some sending server computer used by X Receiving server computer A used by X SMTP SMTP

(8)

E-mail: transfer protocols in the

Internet: examples

• SMTP = Simple Mail Transfer Protocol =

communications protocol used most commonly over TCP/IP links in UNIX environments for transport between mail server computers

• POP = Post Office Protocol

• IMAP = Internet Message Access Protocol

is more powerful than POP; for instance it allows transfer of message headers separately

16

E-mail

using a non-Internet computer

• Through public access e-mail gateways (not free of charge)

»Data-Star in Switzerland »CompuServe in the U.S.A. »...

(9)

*---E-mail:

the UUCP network

• The UUCP network is a collection of computers running UNIX or UUCP-compatible e-mail systems (many PCs and BBS systems have done this).

• A store-and-forward network:

Earlier, it was necessary to know virtually the entire network path a piece of e-mail would take in order to route it. Lately, however, UUCP network

‘administrators’ have been encouraging the adaptation of Internet-style addressing.

18

E-mail:

the Matrix

The Matrix

= all the computers worldwide that can exchange at least electronic mail

= Internet (+ Bitnet + UUCP + FidoNet + centralized e-mail services)

(10)

**--E-mail:

benefits

• Overcomes time zone problems inherent to telephone • Faster than classical mail

• International

• Inexpensive (free of charge in academic institutions) • Data are kept in computer readable form

• Send to more than 1 address in 1 action • Easy to include received message in the reply

• Allows discussion forums & “journals” based on e-mail • ...

20

E-mail: problems

(Part 1)

• How to know the required e-mail address?

• Does your contact person have an e-mail address? • The time period between sending and arriving of a

message is not always known accurately and may be long. • How to communicate with users on other

systems/networks? (using gateways)

• You have to learn to use at least 1 e-mail software/system. • Differences in user interface among various systems • Disk capacity required to store incoming mail

(11)

**--E-mail: problems

(Part 2)

• The user needs access to a computer

• Software required to read, store and retrieve the incoming and outgoing messages

• The user needs some basic understanding of computers and data communication

• The user may suffer from a lack of time »to read and manage the incoming information »to answer messages and queries from persons

communicating by e-mail

22

E-mail:

too much!

(12)

**--E-mail:

structure of messages

Every message in most systems is composed of two basic pieces:

• The header

This contains a series of informative lines which tell the mailing system where to deliver the mail and which provide basic memorandum-like information for the sender and recipient(s).

• The body

This generally consists of free-form text.

24

E-mail in the Internet:

the header

Example:

Date: Friday, 26 March 1993; 22:18:45 EST To: [email protected] (David B. O’Donnell), [email protected]

From: [email protected] (Dr. Julian Bashir) Subject: Failed mail to user [email protected]?

Cc: [email protected]

(13)

E-mail in the Internet:

the body

• The body of e-mail is separated from the header by exactly one blank line.

• The RFC 822 specification does not state what format the body information must appear in, but the vast majority of e-mail on the Internet today consists of eighty-character-wide lines of ASCII text.

26

E-mail: some ways to communicate

with the networks (Part 1)

• NOT connected to a server in a LAN which runs software to receive and send e-mail,

but accessing a gateway computer which acts as a mail server

(for instance Data-Star in Switzerland, Compuserve in the USA)

(14)

**--E-mail using a ‘bulletin board

gateway e-mail computer’

E-mail computer

You The rest of the world

28

E-mail: some ways to communicate

with the networks (Part 2)

Connected directly to a network server computer for a LAN, running the Internet SMTP software and/or the BITNET software to send and receive e-mail:

»using a simple character based terminal OR

»using a more expensive graphics terminal

(15)

**--E-mail from a terminal

connected to a mail server

Terminal

(character-based or

graphics)

no software

Serial line Internet Server

mail editing + mail sending software

Inside Outside

Edit and send on server

30

E-mail: some ways to communicate

with the networks (Part 3)

using a work station with the same operating system as the server

(16)

**--E-mail from a workstation

connected to a mail server

Work station Internet Server mail editing + mail sending software Inside Outside 32

E-mail: some ways to communicate

with the networks (Part 4)

Using a PC with DOS and

a serial line connection with the e-mail server computer: —using only the editing and mail software on the e-mail

server,

—and no program(s) on your microcomputer

(17)

**--E-mail from a microcomputer,

via serial line, using only the server

Microcomputer with DOS

Serial line communications software

Serial line InternetServer

mail editing +

mail sending software

Inside Outside

Edit and send using the server only

34

E-mail: some ways to communicate

with the networks (Part 5)

Using a PC with DOS and

a serial connection with the e-mail server computer: —using PC editing DOS software to edit your messages, —using a DOS serial communications program to send

these messages to the server, and

—using the mail software on the e-mail server computer

(18)

**--E-mail from a DOS microcomputer,

via serial line using PC program(s)

Microcomputer with DOS Text editing software + serial line communications software for DOS

mail server software

Inside Outside

Edit on PC and send message to server; send mail using software on the server

36

E-mail: some ways to communicate

with the networks (Part 6)

Connected directly to a network e-mail server computer: • Using a microcomputer in a “copy & paste” computing

environment (e.g. Macintosh, PC with Windows, ...) and a serial line connection with the e-mail server computer:

»using editing software on the microcomputer,

—using serial communications software to send the message to the e-mail server, with copy & paste —using the e-mail server to send the message

(19)

**--E-mail from a microcomputer

using copy & paste, via a serial line

Microcomputer with

copy & paste environment Text editing software + Serial line communications software

mail server software

Inside Outside

Edit and send message to server , using copy and paste, and

using the mail software on the server

38

E-mail: some ways to communicate

with the networks (Part 7)

Using a PC with network adapter

—with network software without mail module, and using only the mail software on the server computer, OR —with network software without e-mail software, and

using a separate e-mail client program on the PC, OR —with network software which includes a mail module

(20)

**--E-mail from a microcomputer

via a network card / adapter (1)

Microcomputer with DOS Network communications software for DOS without mail module Network

cable InternetServer

mail editing +

Inside Outside

Edit and send message using the server

40

Microcomputer with DOS

Network

communications software for DOS, without mail module, using separate mail client program

E-mail from a microcomputer

via a network card / adapter (2)

Network

cable InternetServer

mail editing +

Inside Outside

Edit and send message using the client mail program

(21)

**--E-mail from a microcomputer

via a network card / adapter (3)

Microcomputer with DOS Network communications software for DOS including a mail module Network

cable Internet_Server

Inside Outside

Edit and send message, using the client mail module on the microcomputer

+ the server mail program on the server

42

E-mail addresses of persons

(Internet style)

An electronic mail address is the string of characters that you must give an electronic mail program to direct a message to a particular person:

username@computer-address Examples:

»(Bitnet: [email protected]) »Internet U.S.A.: [email protected] »Internet not-U.S.A.: [email protected] ****

(22)

?? Question ??

What is your full personal Internet mail address? What is your full personal

Internet mail address?

44

E-mail:

how to find addresses of users?

• With so many computer systems and users in the world, it is impossible to keep a complete “white pages” of the Internet. The problem is compounded because people come and go from the net all the time.

Storing and updating that much information would be an impossible, daunting task.

• Nevertheless, several e-mail address directory services can be found by browsing in the WWW.

• Internet indexes in WWW can also be used to find an address.

(23)

**--E-mail:

reading and managing messages

• On-line =

Linked to the e-mail server computer even when reading and managing messages; for instance:

—using telnet to login to an e-mail computer —using WWW to login to an e-mail computer • Off-line ! =

On-line only to download messages from the server, and reading and managing messages, NOT linked to the server computer anymore !

46

E-mail:

client programs for Unix

From a terminal or from a microcomputer emulating a terminal (using for instance telnet),

using the software on the Unix-based server: »(Line-oriented: mail, mailx,...)

»Screen-oriented: elm, pine,...

(24)

**--E-mail client program for Unix:

Pine

• Was developed by the University of Washington Office of Computing and Communications.

• Is freely available on the Internet via anonymous FTP. • Is designed for ease-of-use with the novice computer user

in mind.

• Is based on Internet mail protocols (e.g. SMTP). • Was originally based on Elm, but has evolved much

since.

48

E-mail client program for Unix:

Pine: features

• Shows a message summary which includes

the status, sender, size, date and subject of messages. • Can view and process mail with the following commands:

forward, reply, save, export, print, delete, capture address and search.

• Offers on-line help specific to each screen and context. • Is very portable and runs on a variety of UNIX machines

(including DECstation, NeXT, VAX and Sun). *---Example

(25)

E-mail client program for Unix:

Pine: ease of use

The guiding principles for achieving ease-of-use in Pine were:

»careful limitation of features

»one-character mnemonic commands »always-present command menus »immediate user feedback

»high tolerance for user mistakes

It is intended that Pine can be learned by exploration rather than reading manuals.

50

Pico:

message composition editor for Unix

• Pico is a message composition editor running on Unix systems, which can be used for instance with the e-mail programs for Unix “elm” and “pine”.

• It is a very simple and easy to use text editor with text justification and a spelling checker.

• You can choose “pico” instead of another editor: for instance in “elm” options at V.U.B.,

choose as standard editor /usr/local/bin/pico -t

(26)

*---E-mail through the WWW:

international systems

• Some international systems based on the WWW allow you to send and read/receive e-mail messages.

Examples: Hotmail of Microsoft, Yahoo! Mail, Gmail of

Google

• Some of these systems allow you to receive/read the messages from the POP mail account provided by your ISP.

Example: Yahoo! Mail

52

E-mail through the WWW:

local systems

• In many institutes, local systems restricted to users of the institute, offer services related to e-mail based on the WWW.

»Example: at the universities in Brussels: http://www.ulb.ac.be/tools/webmail.html ****

(27)

?? Question ??

What may be advantages and disadvantages of using a client for email on the WWW and not on your personal microcomputer? What may be advantages and disadvantages of using a client for email on the WWW and not on your personal microcomputer?

54

E-mail through the WWW:

advantages

• Available from any WWW browser, and thus suitable when traveling.

• Client software dedicated to e-mail on your microcomputer is not required.

• Your e-mail address on a public system may be more stable, may last longer, than an e-maill address provided to you by the institute where you study or work.

(28)

E-mail through the WWW:

disadvantages (Part 1)

• Uses the network inefficiently,

when the sender and the receiver are close to each other, but far away from the e-mail computer.

• Disk space to receive and manage messages in the

international systems free of charge is in most cases more limited than in other e-mail systems.

• Less reliable than good local e-mail systems.

56

E-mail through the WWW:

disadvantages (Part 2)

• Works slower in most cases than using directly an e-mail client on your microcomputer.

• Some systems do not allow »filtering messages

»receiving file attachments

»sending file attachments or sending LARGE attached files • (Not well integrated with e-mail “mailto:” hyperlinks.) • (Advertisements can distract users.)

(29)

E-mail: client programs

for an Internet microcomputer

• From a microcomputer with a network card, you can use a client program which ‘sucks’ / ‘downloads’ the

messages from the local area e-mail network server. • Most of these programs are easier to use than

character-based programs for Unix.

58

E-mail client programs

for an Internet PC with DOS

For DOS, without use of Microsoft Windows: • qvtnet

• NUPOP

• Pine for DOS

• ... *---Examples

(30)

E-mail client programs for an

Internet PC with Windows

• Agent, by Forte!

(added to one of the best Usenet client programs) • Eudora!!

(only for e-mail)

• Outlook Express, and Outlook, by Microsoft!!!

(for e-mail and Usenet text messages) • Pegagus mail!

(only for e-mail)

60

E-mail + WWW client programs for

an Internet PC with Windows

• Netscape

(combined with a good WWW browser and a simple Usenet client)

(31)

PC Eudora for Windows:

positive properties (Part 1)

• Allows sending and receiving binary, non-ASCII files, named attachments which are automatically encoded and sent, and decoded when received.

• Can be used also off-line to read, manage and compose messages.

62

PC Eudora for Windows:

positive properties (Part 2)

• Eudora for Macintosh is also available, with a similar user

interface; that offers several advantages:

»makes support by the network managers simple in a heterogeneous (PC + Macintosh + Unix) environment »allows PC and Macintosh users

—to discuss the common features and problems —to communicate using the advanced features

(such as exchange of attachments of ASCII and non-ASCII files as attachments to messages) **--Example

(32)

PC Eudora for Windows:

screen capture

64

?? Question ??

Which method for e-mail do you or will you use? Which method for e-mail

do you or will you use? ****

(33)

!! Task - Assignment - Exercise !!

Read your incoming mail. Send a simple ASCII message

(for instance to yourself). Read your incoming mail. Send a simple ASCII message

(for instance to yourself).

66

!! Task - Assignment - Exercise !!

Send an e-mail message to more than 1 person at the same time, in 1 action.

(34)

--!! Task - Assignment - Exercise --!!

Create, save and test a network signature for your own messages.

68

!! Task - Assignment - Exercise !!

Forward an e-mail message to a third person. Forward an e-mail message

to a third person.

(35)

--?? Question --??

What is the difference between a carbon copy

and

a blind carbon copy? What is the difference between

a carbon copy and

a blind carbon copy?

70

?? Question ??

What is the difference between cc and bcc in email?

In which case would you use bcc? What is the difference between

cc and bcc in email? In which case would you use bcc?

(36)

**--E-mail: reading and managing

messages off-line

Off-line = using only a microcomputer, NOT on-line linked to the server, after downloading messages from the server to read and manage those messages, using one of the following types of programs

a dedicated off-line mail reading program

»a more general program, for instance a program for text editing /word processing

»an e-mail client program which can be used on-line connected to the server, as well as off-line (e.g. Eudora)

72

?? Question ??

Can you send and receive other information types than simple text and numbers

by electronic mail? Can you send and receive

other information types than simple text and numbers

by electronic mail?

(37)

***-E-mail

more than ASCII text and numbers

Transmission of data other than ASCII texts is possible by • encoding a non-ASCII file to ASCII,

• enclosing it in the message, and

• decoding the file to the original non-ASCII file at the receiving end.

74

E-mail: non-ASCII files

encoding / decoding

• This works manually or automatically:

»Manually: sender encodes to ASCII + receiver decodes »Automatically / transparently for the user, in some

advanced systems (for instance Eudora) • Coding schemes used:

»UUencode / UUdecode .UUE-files

»BinHex .HQX-files

»MIMEQP = MIME Quoted-Printable »...

(38)

**--E-mail: MIME = Multipurpose

Internet Mail Extensions

MIME builds on the older standard by standardizing additional fields for mail message headers that describe new types of content and organization for messages.

76

E-mail:

aims of MIME

MIME allows mail messages to contain: »multiple objects in a single message

»text having unlimited line length or overall length »character sets other than ASCII

»multi-font messages

»binary or application specific files

»images, audio, video and multi-media messages

(39)

**--E-mail: MIME:

compatibility with older standards

MIME is designed to be compatible with older Internet mail standards.

In particular, it is compatible with RFC 822:

If a mail reading program receives a message that is a MIME message then it will likely perform additional processing for the MIME message that it would not perform for non-MIME messages.

78

E-mail: MIME:

how it works

• In order to allow mail reading programs to recognize MIME messages, MIME messages are required to contain a MIME-Version header field.

• The MIME-Version header field specifies the version of the MIME standard that the message conforms to.

(40)

**--E-mail: the MIME Quoted-Printable

message encoding scheme

• Most appropriate for data that consist primarily of printable ASCII characters.

• Printable ASCII character are represented as themselves. • The equals sign (=) serves as an escape character:

Any character that is not a printable or white space ASCII character is represented as =, followed by two hexadecimal digits.

(An = in the message is also represented in this way.) • Lines that are longer than 76 characters are cut off after

the 75th character and the line ends with an equals sign.

80

E-mail: MIME Quoted-Printable:

advantages

• Only few additional characters are required. In other words, encoding does not make the message much bigger. • The message can be read by people who do not have a

MIME aware mail reading program.

(41)

---?? Question ---??

Which kind of files can be sent as attachments?

82

!! Task - Assignment - Exercise !!

Send a simple text e-mail message to yourself, receive it, and read it.

Send a non-text file to yourself, by e-mail, receive it, and view or execute it (for instance a word processing file). Send a simple text e-mail message to yourself,

receive it, and read it.

Send a non-text file to yourself, by e-mail, receive it, and view or execute it (for instance a word processing file). ****

(42)

E-mail file attachments:

a few practical tips

• Files take normally longer to send and download than messages. So send files only when necessary.

• If the file is large, use a utility before sending to compress the file (for instance by “zipping” the file).

• If you want to send more than 1 file that should be kept together, the consider not sending multiple attached files, but compressing them all into 1 using some utility

program.

84

!! Task - Assignment !!

Read Brain, Marshall How e-mail works. [online]

Available from:

http://computer.howstuffworks.com/email.html Read

Brain, Marshall How e-mail works. [online]

Available from:

http://computer.howstuffworks.com/email.html

(43)

***-E-mail:

organisation of your mailboxes

• Incoming and outgoing e-mail messages can be stored in an In and Out mail box.

• More mailboxes can be created however.

• Thus e-mail software can help you managing your work. • Examples of useful additional e-mailboxes:

»To do (normal)

»To do (only when Internet can be accessed) »To follow up

»A mailbox for each of your subjects / activities / interests

86

?? Question ??

How have you organised your e-mailboxes? How have you organised

your e-mailboxes?

(44)

--?? Question --??

Compare the communication media fax and electronic mail. Compare the communication media

fax and electronic mail.

88

Fax

Black and white images

E-mail versus fax: types of

data/information transmitted

E-mail ASCII (unformatted text + numbers + Postscript documents) +

data encoded to ASCII

(formatted text, programs, sound, images, video, multimedia,...)

(45)

**--E-mail versus fax:

requirements

Fax Fax machine or fax card + fax software (+ scanner) Telephone network E-mail Computer + e-mail software Data communications network or telephone network Hardware + software required Communications network 90

E-mail versus fax:

further comparison

Property Time between

sending and receiving Suitability of received data for manipulation on computer Costs Fax Immediately E-mail Can be immediately ☺ ☺

(46)

**--E-mail for access to

information resources

• electronic mailing lists (unmoderated or moderated) • electronic newsletters and journals

(those which are distributed by e-mail) • current awareness services

• other computer network based information sources which can better be accessed with other, more interactive

methods: for instance:

• computer archives accessible with anonymous ftp

92

Netiquette = network etiquette:

some of the important rules (Part 1)

• Cover only one subject per message.

• Include a meaningful subject description in your message. • Do not type messages in all caps.

• When summarizing, summarize. • Be brief.

• In the case of a question: begin the subject line with a ?

(47)

**--Netiquette = network etiquette:

some of the important rules (Part 2)

• Beware of making strong, emotional, angry or sarcastic statements.

• When responding to a message,

»either “attach” the original message (if it is short),

»or lead your response with a clear reference to the original message.

• Keep your messages relevant to the topic of

an e-mail - based discussion list or Usenet Newsgroup.

94

Network communication:

smileys / emoticons

:-)

expresses “happiness”.

• This odd figure is one of the ways a person can portray “mood”, in the very flat medium of computers:

by using “smiley faces” = “smileys” = “emoticons”, figures created with the symbols on the keyboard. • There are literally hundreds of such symbols, from the

obvious to the obscure.

• Read with your head tilted to the left (90 degrees).

(48)

**--Network communication:

abbreviations used (Part 1)

• BFN bye for now

• BTW by the way

• FAQ frequently asked question • FUBAR fouled up beyond all recognition • FWIW for what it's worth

• FYI for your information

• IAE in any event

• IMHO in my humble opinion

• IMNSHO in my NOT so humble opinion

96

Network communication:

abbreviations used (Part 2)

• IMO in my opinion

• IOW in other words

• OTOH on the other hand

• ROTFL roll(ing) on the floor laughing

• RSN real soon now (may be a long time coming) • RTFM read the [f...] manual (or message)

• TANSTAAFL there ain't no such thing as a free lunch

• TIA thanks in advance

• TYVM thank you very much **--Examples

(49)

!! Task - Assignment - Exercise !!

Try to avoid email spam

by reading and applying the following guidelines:

Center for Democracy & Technology

Why am I getting all this spam? [online]

Available from:

http://www.cdt.org/speech/spam/030319spamreport.shtml [cited December 2003]

Summary Major findings Tips for avoiding spam

Try to avoid email spam

by reading and applying the following guidelines:

Center for Democracy & Technology

Why am I getting all this spam? [online]

Available from:

http://www.cdt.org/speech/spam/030319spamreport.shtml [cited December 2003]

Summary Major findings Tips for avoiding spam

98

Data communication:

overlap among services

• Electronic mail requires on-line access to a mail computer.

• Electronic mail may allow searches of a database. »e.g.: archie; listserv databases;...

• Electronic mail may include or allow transfer of a file. »e.g.: MIME; BITFTP;...

• Remote login may include e-mail and file transfer. »e.g:WWW; BBS's with downloading;...

(50)

**--E-mail:

future trends

• more users

• availability of global e-mail address directories

• from simple text to multimedia and hypermedia e-mail • from simple ASCII text e-mail

to voice e-mail, to Internet telephone,

to network video-conferencing

100 • You are free to copy, distribute, display this work under

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You must mention the author.

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