How e-mail works in brief

The mails you send will be temporarily saved in your mail server. Email servers accept, forward, deliver, and store messages. Neither the users nor their computers are required to be online simultaneously; they need connect only to an e-mail server, to send or receive messages. Mail serveris also used to mean a computer acting as a Mail Transfer Agent (MTA) that isrunning the appropriate software.

Using emails

Email address.An Email address has 3 parts in it. If we type an email address, it will be in the following format.

Eg: username@hostname

1 2 3

1:-The first part identifies the user. Usually case sensitive. 2:- The @ sign which comes in between

E-mail address breakdown

support@computerhope.com

· The first portion all e-mail addresses, the part before the @ symbol, contains the alias, user, group, or department of a company. In our above example support is the Technical Support department at Computer Hope.

· Next, the @ (at sign) is used as a divider in the e-mail address;

· E-mail clients

· An email client is a computer program used to access and manage a user's email. It is also referred to as an e-mail reader or a Mail user Agent (MUA). It can refer to any system capable of accessing the user's email mailbox, regardless of it being a mail user agent, a relaying server, or a human typing on a terminal. In addition, a web application that provides message

4. SMTP, POP3, IMAP protocols.

More about E-mailing concepts

The SMTP Server

When we send an email, our computer connects to our email service‟s mail server. A server is a centralized computer which manages a specific type of service. An email server for instance, handles emails. The email server responsible for sending emails is called the SMTP (Simple Mail Transfer Protocol) server. One SMTP server can pass on the mail to another SMTP server and relay it to the destination through several hops.

Every email has the sender‟s address (e.g. sender@sendermail.com) and the recipient‟s in the To

Field (e.g. recipient@recipientmail.com). When an email is sent, the email client connects to the

SMTP server of the sender‟s email service (e.g. mailserver.sendermail.com). The client transmits the address of the sender, the address of the recipient and the content of the message.

The SMTP server goes to work at locating the whereabouts of the recipient. Using the recipient‟smail ID(i.e. recipient@recipientmail.com) it locates the domain name–e.g.recipientmail.com.

Each domain name represents a unique Web address, called an Internet protocol (IP) address. Think of it as postal addresses of the internet. The link between domain names to their IP addresses is stored in the Domain Name Registry. The SMTP server then contacts the server where the registry is kept (The DNS Server). The DNS server sends back the address to the SMTP server.

The SMTP server then proceeds to hand over the email to the SMTP server of the recipient‟s email service (let‟s call it mailserver.recipientmail.com). This SMTP server checks and confirms that the mail addressed to recipient@recipientmail.com belongs to it and hands it over to its counterpart, the POP3 server (or the IMAP server).

The POP3 Server

Post Office Protocol (POP3)servers are the servers that do the job of receiving mails. The number ‘3’ is the version number of the protocol in use. POP3 servers have mail accounts (our email IDs). Each mail account is mapped to a username-password combination. Once the message is handed over to the POP3 server, it is kept and stored in the mail account till the recipient logs in and checks the mail.

The IMAP Server

An email client connects to the POP3 server and tells it to allow download of the email. Once downloaded to the local machine, POP3 mailboxes do not retain a copy of the email. Thus, you cannot check your emails from another PC as it has already been downloaded. To tack this difficulty, IMAP was introduced. IMAP (Internet Message Access Protocol version) simply retains a copy of the emails on the server. This allows you to access your e-mail from any location with an internet connection.

Questions:

1. What is a „mail server‟? Describe how to send an e-mail between two people.

2. What is an e-mail client? Name two types of e-mail clients with examples.

3. Definethefollowingterms.

SMTP

DNS Server

4. What are the advantages of POP sever and IMAP server?

5. When sending an e-mail what is the difference between CC and BCC?

6. How can you attach a document to your e-mail?

7. List three e-mail etiquettes and give reasons for doing them.

8. What are the three parts of an e-mail address?

9. When creating an e-mail account what is the purpose of typing a given code in the cage provided?

10. What is the purpose of “inbox” in an e-mail account?

References

1. June J. Parsons and Dan Oja, New Perspectives on Computer Concepts 16th Edition - Comprehensive, Thomson Course Technology, a division of Thomson Learning, Inc Cambridge, MA, COPYRIGHT © 2014.

2. Lorenzo Cantoni (University of Lugano, Switzerland) James A. Danowski (University of Illinois at Chicago, IL, USA) Communication and Technology, 576 pages.

3. Craig Van Slyke Information Communication Technologies: Concepts, Methodologies, Tools, and Applications (6 Volumes). ISBN13: 9781599049496, 2008, Pages: 4288

4. Utelbaeva A.K.,Utelbaeva A.K. Study guide for lectures on discipline “Computer science”, Shimkent 2008, 84 pages.

Lecture №10. Cloud and Mobile technologies.
Purpose:The purpose of this lecture is to analyze current trends in hardware, leading to the emergence of cloud computing technology.
Plan:
1.Date centres. Tendencies of development of the modern infrastructure decisions.

2. Principles of cloud computing. Technologies of virtualization. Web service in the Cloud.

3.Main terms and concepts of mobile technologies. Mobile services. Standards of mobile technologies.

1.Date centres. Tendencies of development of the modern infrastructure decisions.

Data center (from the English data center.), оr center (and storage), data (data center / TSHOD) - is a specialized building for the accommodation (hosting) server and network equipment and connecting users to the Internet channels,

Data Center performs processing functions, storage and dissemination of information, usually in the interest of corporate clients - it is focused on solving business problems by providing information services. Data centers are typically located within or in proximity to the node or connection point prisutstviyakakogo any one or more carriers. Quality and channel bandwidth does not affect the level of service as the main criterion for evaluating the quality of any data center is the server availability.

Modern infrastructure solutions.
Every year for the continuity of the business services requirements increase, and obsolete equipment to ensure the smooth functioning of virtually impossible. In this regard, the largest IT vendors produce and implement a more functional and reliable hardware and software solutions. Consider the basic tendencies of development of infrastructure solutions, which, one way or another, contributed to the emergence of cloud computing concept.

Growth performance computers. The advent of multi-core and multi-processor computer systems, the development of blade systems
1.The emergence of systems and storage area networks
2. Infrastructure Consolidation
The advent of blade systems

In the development of computer technology has always existed a large class of problems that require a high concentration of computing resources. These include, for example, complex high-performance computing (scientific problems, mathematical modeling), as well as maintenance tasks large number of users (distributed databases, Internet services, hosting). Increasing the number of computing units in the data center requires new approaches to the placement of servers, and also leads to an increase in premises costs for data centers, their power, cooling and maintenance. What is the Blade-server? By definition, this market research firm IDC Blade-server or blade - a modular single-board computer system that includes a processor and memory. The blades are inserted into a special chassis with a backplane (backplane), providing them a network connection and power supply.

The emergence of systems and storage area networks
Another feature of the modern history of the development of computer systems, along with the advent of blade servers, was the emergence of specialized systems and storage area networks. Internal storage subsystem servers often could not provide the required level of scalability and performance under a cascade of increasing the volume of information processed. As a result, there were external storage systems focused exclusively on the decision of the data storage tasks and providing data access interface for their use.