INTERNET AND EMAIL NOTES

 

MSIMBAZI CENTRE TRAINING INSTITUTE

INTERNET AND EMAIL NOTES

 INTERNET

It is a large network of networks that covers the whole world and enables millions of computers from different organizations and people to communicate globally.

Importance of Internet

The importance of internet can be seen through its contribution to:-

a)      Research activities

b)      News and information dissemination.

c)      Leisure

d)      Communication.

e)      Business Transactions, etc.

Requirements for Internet Connectivity

(a)   Telecommunication facilities

Internet relies on telecommunication facilities like telephone lines, telephone exchange station and satellite transmission in order to cover the whole world.

(b)   Modem (Modulator-Demodulator)

It is a special digital to analog interface card that changes data from digital to analog so as to be transmitted on telephone lines and on receiving end the data is changed from analog to digital for the computer to understand.

(c)    Internet Service Providers (ISP’s)

These are companies that offer internet services to end users. They provide the Internet services to end users at a fee.

Examples of ISP in Kenya include:

1.      Liquid Telecom

2.      Access Kenya

3.      Zuku

4.      Faiba

5.      Orange Kenya

6.      Safaricom

 

(d)   Internet Software

Internet software help facilitate your access to the Internet. To achieve communication between computers special software called Protocol is needed.

 

INTERNET SERVICES

1.      E-mail

This is the exchange of electronic letters, data and graphics on the     internet.

2.      Electronic Learning (E-learning)

This is learning through interaction with special programs on the computer.

3.      Electronic Commerce (e-commerce)

It refers to buying and selling of goods and services over the internet.

4.      World Wide Web (WWW)

In order to connect a network to the internet, the local area network needs an internet server. This server is given the name world wide web (www) and has all the information which others on the internet access.

 

ACCESSING THE INTERNET

Software applications that enable the user to access information on the internet are called Web Browsers. Examples of web browsers include:  

·         Mozilla Firefox

• Netscape Navigator  
• Google Chrome
• Opera
• Internet Explorer
• Netscape Navigator
• Safari

I    Login/ Sign In

To access a website, type the full address of the website on the address bar, then press the enter key.

Surf/ Browse

Surfing/ Browsing is the process of accessing Internet resources like web pages and websites.

Hyperlinks

A hyperlink is a text or picture on an electronic document that causes other web pages to open when the link is clicked.

Search Engine

This is a program that searches documents for specified keywords and returns a list of the documents where the keywords were found. Examples of search engines include: Google, Yahoo, Bing, Ask, WebCrawler, etc.

 

Downloading

This refers to the process of transferring information from the internet to a local storage e.g. a computer, flash disk, etc.

Uploading

Refers to the process of transferring a file /files from your computer to the Internet.

 

ELECTRONIC MAIL (E-MAIL)

Electronic mail refers to the sending and receiving of electronic letters and documents on the internet.

E-MAIL SOFTWARE

E-mail software falls under communication software that are designed to help the user to read and send individual text documents on the internet so long as the sender and receiver have an e-mail address. Examples of e-mail software include: Gmail, yahoo, hotmail, outlook express, thunderbird, etc.

 

E-MAIL FACILITIES

1.      MAILS

a)      Checking Mail

In order to check mail the user has to open the e-mail account by providing the correct username and password. In e-mail account, click the Inbox command to view a link list of all received mails.

b)     Compose a Mail

Composing implies writing. To compose a message, click the Compose command.

c)      Send Mail

To send mail, type the correct e-mail address of the recipient, and then click Send command.

d)     Forward Mail

A received mail can be forwarded to another recipient. After reading, click the Forward command and then provide the address of the recipient.

2.      FILE ATTACHMENT

E-mail software enables a person to attach other files like pictures, music, movie clips, etc to an e-mail for sharing with others before sending. The source of attached files can be from the hard disk or other storage devices.

3.      ON- LINE MEETING

It is possible to hold an on-line meeting with people by sending mails to them e.g. on-line interviews may involve a person sending electronic mail composed of interview questions to a recipient who can read and answer back.

4.      TELEPHONE MESSAGES

Wireless Access Protocol (WAP) makes it possible to send e-mail to a mobile handset and a mobile message to e-mail account.

5.      CONTACT MANAGEMENT

Most mail programs allow the user to develop an address book which holds contact information like e-mail address of different people.

 

E-MAIL ADDRESS FORMAT

A typical e-mail address would look like this: chemwex@yahoo.com

Chemwex is the username and is usually created by the user during e-mail account registration.

@ is the symbol for “at” which separates the user name from the rest of the address.

Yahoo.com is the name of the host computer in the network i.e. the computer on which the e-mail account is hosted.

Com identifies the type of organization offering a particular service(s) and is called the domain, meaning it is a commercial institution.

 

OTHER COMMONLY USED DOMAINS INCLUDE:

DOMAIN	TYPE
.edu	Educational Institution
.gov	Government Institution
.org	Non- profit making organization
.mil	Military organization
.co	Commercial Institution
.net	An institution or organization providing networking services
.ac	An academic institution

 

E-MAIL COMPOSE WINDOW

A typical e-mail compose window has three basic elements:

1.      HEADER: The e-mail header is made up of the following parts:

(a)   Addresses of the Recipients: The e-mail recipients can be more than one.

(b)   Subject: Presents the topic of the message.

(c)    Attachment: Files attached from other programs such as word processors and spreadsheets.

2.      MESSAGE: This is the content of the email. It is typically short and to the      point. It may include text and graphics.

3.      SIGNATURE: The signature provides additional information about the sender such as full name, address and telephone number. 

Email Attachment

An email attachment is a computer file sent along with an email message. One or more files can be attached to any email message, and be sent along with it to the recipient. This is typically used as a simple method to share documents and images.

History, and technical detail

Originally, ARPANET, UUCP, and Internet SMTP email allowed 7-bit ASCII text only. Text files were emailed by including them in the message body. In the mid 1980s text files could be grouped with UNIX tools such as bundle and shar (shell archive) and included in email message bodies, allowing them to be unpacked on remote UNIX systems with a single shell command.

The COMSYS/MSGDMS system at MIT offered "Enclosures" beginning by 1976. Users inside COMSYS could receive the enclosure file directly. Messages sent to users out of the COMSYS world sent the enclosure as part of the message body, which was useful only for text files.

Attaching non-text files was first accomplished in 1980 by manually encoding 8-bit files using Mary Ann Horton's uuencode, and later using BinHex or xxencode and pasting the resulting text into the body of the message. When the "Attachment" user interface first appeared on PCs in cc: Mail around 1985, it used the uuencode format for SMTP transmission, as did Microsoft Mail later.

Modern email systems use the MIME standard, making email attachments more utilitarian and seamless. This was developed by Nathaniel Borenstein and collaborator Ned Freed - with the standard being officially released as RFC2045 in 1996.

With MIME, a message and all its attachments are encapsulated in a single multipart message, with base64 encoding used to convert binary into 7-bit ASCII text - or on some modern mail servers, optionally full 8-bit support via the 8BITMIME extension.

Size limits

Email standards such as MIME do not specify any file size limits, but in practice email users will find that they cannot successfully send very large files across the Internet.

This is because of a number of potential limits:

• Mail systems often arbitrarily limit the size their users are allowed to submit.
• A message will often pass through several mail transfer agents to reach the recipient. Each of these has to store the message before forwarding it on, and may therefore also impose size limits.
• The recipient mail system may reject incoming emails with attachments over a certain size.

The result is that while large attachments may succeed internally within a company or organization, they may not when sending across the Internet.

As an example, when Google's Gmail service increased its arbitrary limit to 25MB it warned that: "you may not be able to send larger attachments to contacts who use other email services with smaller attachment limits".

Also note that all these size limits are based, not on the original file size, but the MIME-encoded copy. The common Base64 encoding adds about 37% to the original file size, meaning that an original 20MB file could exceed a 25MB file attachment limit. A 10MB email size limit would require that the size of the attachment files is actually limited to about 7MB.

Malware

See also: Spamming

A lot of malware is distributed via email attachments with some even considering such to be the main vector for cyberattacks on businesses. Users are advised to be extremely cautious with attachments and to not open any attachments that are not from a trusted source and expected − even if the sender is in their address book as their account might have been taken over or misused. While many email servers scan attachments for malware and block dangerous filetypes, this should not be relied upon − especially as such cannot detect zero-day exploits.

Dangerous file types

Email users are typically warned that unexpected email with attachments should always be considered suspicious and dangerous, particularly if not known to be sent by a trusted source. However, in practice this advice is not enough – "known trusted sources" were the senders of executable programs creating mischief and mayhem as early as 1987 with the mainframe-based Christmas Tree EXEC.

Since the ILOVEYOU and Anna Kournikova worms of 2000 and 2001, email systems have increasingly added layers of protection to prevent potential malware. Now, many block certain types of attachments.

 ATTACHING FILES INTO AN E-MAIL

1.      Click the Attachment button on the toolbar.

2.      In the Dialog box that appears, select the file/ files to attach.

 

3.      Click Attach button to attach the files.