Computer Network: Electronic Mail Server Essay

Project Proposal

This project is exclusively developed to describe and demonstrate the operation and significance of an electronic mail server. This project proposal, together with drafts and diagrams of related documents, will be extensively used by a networking management team of an organization or computer network practitioners, in order to determine whether to approve work that is developed on this project. Furthermore, a clear as well as precise plan assists in setting expectations which will be used at later stages for evaluating the success of the project. This project mainly focuses on the technology underlying the electronic mail servers and basically what are electronic mails (LearntheNet.com, 2010).

Background

Electronic mail, or e-mails, as they are known to its many fans, has been in use for more than two decades. Earlier, in 1990, it was mainly used in academia. Throughout the 1990s, e-mails became known to the masses at large and developed rapidly and exponentially till the extent where the number of e-mails sent out per day is nowadays vastly more than the number of paper letters (Vleck, 2008). In practice, the major problem of sending messages to various different email addresses is typically solved by entering a list of multiple addresses separated by comma within the “To”, “BCC”, or “CC” fields of the message. However, there are two significant reasons why some SMTP mail servers programs do not support this technique:

1. They are not Spam programs. Adopting this technique for sending messages is frequently exercised while sending unsolicited and malicious commercial e-mails.
2. This method does not involve quick message delivery whenever the SMTP server is loaded across a user’s computer (LearntheNet.com, 2010) (Vleck, 2008).

However, if the user enters multiple addresses within the ‘CC’ (carbon copy) or ‘BCC’ (blind carbon copy) fields of their e-mail message, the mail server program will send the e-mail message only to the first 50 consecutive e-mail addresses, thereby ignoring the remaining addresses. Gradually, when experience was gained, even more elaborate systems were proposed. During 1982, the ARPANET email proposals were issued as RFC 821 and RFC 822 which are specifications for transmission protocol and message format respectively. However, minor revisions like RFC 2822 and RFC 2821 have become Internet standards. Nevertheless, everyone still relate to Internet email as RFC 822 (Tanenbaum, 2005) (Kawamata & Jiro, 2001).

Indeed, in 1984, CCITT enlisted its X.400 recommendations. Two decades later, email systems on the basis of RFC 822 have been widely used, whereas those based on X.400 have vanished. The reason behind RFC’s success is not its good features, but because X.400 was so complex and poorly designed that nobody was able to implement it well. Additionally, given an option between simple minded and working RFC 822 based email system and a non-working X.400 email system, most of the enterprises chose the former (Vleck, 2008).

Server Problems to be addressed

Some of the complaints are as follows:

Messages had no internal format or structure, thereby making computer processing difficult. For instance, if a forwarded message was added to the body of another message, it was difficult to extract the forwarded part from the received message. 2. Sending a message to a specific group of persons was cumbersome. This facility is often needed by managers in order to send out memos to all of their subordinates. 3. The sender would never know if the message reached the destination or no. 4. The user interface was weakly integrated wherein the transmission system required users to first edit the file, leave the editor, and the invoke the file transfer program. 5. If a network user was planning to be away for several weeks on business and wanted every inbound e-mail to be managed by his secretary, this was extremely difficult to arrange. 6. Lastly, it was not very possible to create messages containing a combination of text, images, voice, videos, facsimile, and send them to the recipient (Tanenbaum, 2005). Indeed, when such a message is directed towards the ISP’s server, it creates copies of the original e-mail message corresponding to the number of addresses entered in the aforementioned fields. Afterwards, the server then sends every copy of the original message to the server; the ultimate outcome is precisely similar to the event as if a different message was being sent to every address on the list. Rather than resolving the problem, it has only been worsened. Furthermore, the server which must deliver those messages ends up producing congestion across the Internet, as a result of which its performance degrades. And no administrator acknowledges or appreciates such things, and almost all ISPs immediately close the accounts of the network users who attempt to send a huge number of messages at the same time (LearntheNet.com, 2010) (Kawamata & Jiro, 2001).

CC and To Fields: In cases when several addresses are being entered within the ‘To’ & ‘Cs’ fields, every recipient would be able to view every other recipient’s address from a user’s list. Then, the message would be seen very unprofessionally created (LearntheNet.com, 2010). Consequently, the marketing effect created by such a sending technique is highly unfavorable because of two main reasons:

Firstly, if the message to be sent is not personalized; that is, it is not addressed personally to the recipient. 2. Secondly, if the user was so unprofessional or careless to expose their entire mailing list to everyone’s sight; hence, to what extent can a user expect that the customers would be motivated to buy his goods or services and reveal their confidential and sensitive information, such as credit card data, user names, passwords, etc, to him? (LearntheNet.com, 2010)

BCC Field: The BCC field holds its significance in the fact that when a user enters recipient email addresses within the Bcc field of the message, the recipient would not be able to see the addresses in the list in a similar fashion as they are inserted into the ‘CC’ as well as the To’ fields. Furthermore, to make a particular message reach its target address and make the server accept it, it is extremely essential to enter a certain value within the ‘To’ field. This value, in turn, will be the same for every recipient and therefore, if a user enters, for example, [email protected], each message recipient will be able to see that address wherein his /her personal address must be (LearntheNet.com, 2010) (Oricode, 2010).

Whenever the server, at which the mailbox indicated by the corresponding address in the sender’s list is situated, accepts a message like this one, it may recognize it as Spam. Moreover, automated mechanisms are employed for blacklisting people who intend to send out Spam mails; of course everything relies on the software loaded at the server end and the administrator end. A message created by a user contains adequate information about them. Deactivating the account with the respective ISP is one of the steps which could be applied (Tanenbaum, 2005). Email, similar to most other types of communication, is equipped with its own styles and conventions. In particular, it is extremely informal and also contains a relatively low threshold of use. Moreover, the reason why it is worth confronting and solving the problem mentioned above is that people who would not think of writing a letter or even calling up to a very important person do not show any hesitation to send an informal and sloppily crafted e-mail. E-mail can be exchanged with people all around the world. Not only that, it also provides a economical, fast and a convenient way to sends out messages to friends, colleagues, and family (LearntheNet.com, 2010).

This project will produce a detailed description of what electronic mails are, their significance, features of emails, architecture as well as services. Apart from this, the project also throws light on the user agents involved, format of an email, and the various protocols involved in the development of an electronic mail (Oricode, 2010). However, this project will not talk about the message format of an email in depth. The message format is covered superficially in this project report.

Clear diagrammatic illustrations of the working of emails, how they are created and sent by the sender and viewed and read by the recipient are exclusively elaborated in a section dedicated to it. This project also provide and overview of the how Windows Server 2003 can be used as a messaging solution and the supporting technologies to aid the working of Electronic mails. Furthermore, this project can be tested on technologies such as Outlook Express and Microsoft Outlook where the client is configured for providing the best outcome and email service. The research paper deals with the various electronic mail server requirements along with a list of most efficient mail servers (Oricode, 2010) (The FreeBSD Documentation Project, 2010). The above mentioned bottlenecks or problems is accurately addressed by this project, by providing appropriate solutions and remedies that are derived exclusively from a number of diverse technologies, protocols, design and structures. The following plan has been used to manage and evaluate the project. Moreover, the primary assumptions affecting the project plan are also documented below:

• What is an Electronic mail?
• Email programs
• Server Requirements
• Architecture and Services
• Messaging Protocols
• Message Formats
• Windows Server 2003 as a Messaging solution
• Supporting technologies
• Internet Black and White Lists

Moreover, the project also deals with how envelopes and message are distinguished into paper mail and electronic mail. A diagrammatic representation of how current technologies have been deployed and put to use for the development of electronic mails systems and their enhanced features to meet all possible requirements of the user and to offer them an excellent experience of emailing and communication.

The project report also presents the numerous benefits electronic mails have on user all across the globe backed by the efficiency in operation of the electronic mail servers. Significantly, the format of the email messages is also spoken of in this project report. These message formats have been evolved along with the evolution of electronic mails, and thus becomes much more beneficial for a user to precisely specify how the e-mail should look when received by the recipient, that is, the structure of the body of the email, how easily it may be read by the receiver, and finally, to whom all the message should be reached. This project is tested on the client side components such as Microsoft Outlook and Outlook Express. Supporting technologies which enhance the electronic mailing services within Windows Server 2003 is also elaborated in this documentation. Additionally, it also talk about its benefits in an organization that requires additional functionality as well as collaboration capabilities who aim at utilizing these supporting technologies.

A brief but a descriptive illustration of the concept of Internet black and white lists is also presented in this project report. The problem of back lists and white lists are addressed by presenting an effective solution that can be comprehended by users of all types. Apart from this, the research paper examines the major causes of failure encountered by enterprise email systems, together with offering preventative measures in order to reduce the percentage of unplanned email outages (IBM, 2006). These failures are directly related to Storage Area Network, Hardware server, Database corruption, Connectivity losses, and Natural disasters. This research paper also talks about the various security measures to be taken by users and network administrators while using the e-mail services. Techniques to be adopted by users to avoid misuse of any of their confidential information, attacks and viruses the emails are prone to, and security measures users must undertake, are covered in this research paper. The project is developed to be used by a computer user who uses emails to send mails and messages to numerous recipients across the world, network administrators who will deploy the project at the company servers or on standalone PCs, and any networking personnel who are capable of dealing with and expertise in electronic mail servers.

Executive Summary

Electronic mails or e-mails have lately become the most permeate kind of business communication. Emails have been enforcing a deeper impact on very aspect of enterprises, small or big, thereby enhancing the quality of communication amongst employees, management executives, clients, vendors, stakeholders, as well as business partners. E-mail systems continue to degrade in performance, even when large-scale enterprise investments are made in replication, tape back up systems, etc. Furthermore, as it is known that man-made as well as natural disasters may result in e-mail outages, new research studies have shown that e-mail systems are usually turned down by failures in technologies (IBM, 2006).

This research paper not only gives an in-depth study of what email servers and systems are, but also covers their features, and underlying protocols that supports their operations. The paper also studies the major causes of email system failures at enterprise level and also provides an efficient guidance in order to reduce the probability of the occurrences of such unintentional e-mail outages. The research paper aims at addressing the practical problem of sending out messages to various e-mail addresses by entering a list of email addresses separated by comma, in the ‘To’, ‘CC’ and ‘BCC’ fields of an email message. The very first email systems consisted of file transfer protocols, which required the convention that the first line of the message should contain the recipient’s address. However, as time passed, the limitations of this approach became even more obvious (IBM, 2006). Therefore, this research study was written to provide an in-depth study of the developments of the e-mail systems, requirements of an e-mail server, and the protocols and technologies on which an e-mail server depends.

Introduction to Electronic mail systems: The Internet electronic mail system is stated as one of the most essential and important resources in the Internet services. With the e-mail system, one can exchange electronic mail with people across the globe. Moreover, it offers an economical fast and a convenient way to send messages to colleagues, friends, and family.

Speed: E-mails are much faster as compared to traditional mails. An e-mail message is capable of traveling around the world within minutes.

Cost: When an Internet user pays a service provider for a connection to the Internet, no extra charge is applied for sending and receiving e-mails. Moreover, an Internet user does not have to pay extra charges even if they send a long message to a recipient across the globe. Exchanging e-mails can possible save you money over long distance calls as well. Convenience: One does not need to buy and stick stamps for e-mails and drop the emails into one’s mailbox. Only an e-mail program is required to help a user send, receive, and manage their emails (Lewis, 2008) (Kawamata & Jiro, 2001) (The FreeBSD Documentation Project, 2010). An electronic mail server is a computer which moves and stores mails across networks and over the Internet. In other words, in order to enable a computer to become an electronic mail server, the computer should have the ‘mail server’ software installed in it. Moreover, a mail server is capable of sending as well as receiving mails.

For sending mails, the mail server software employs SMTP, short for, Simple Mail Transfer Protocol (Lewis, 2008). The working of SMTP is explained below:

1. The mail client that is the software used for composing or creating the email, such as Outlook Express, sends the mail to the mail server which is already configured within the software package of the mail client. The SMTP server configuration stores the mail server’s address.
2. The SMTP server analyzes the “To”, “Cc”, and “Bcc” field addresses in order to find out which server the email is supposed to reach.
3. Eventually, the SMTP server sends the e-mail to the destination mail server.

Due to the latest trend of spam mails, certain SMTP servers are getting increasingly sophisticated. Indeed, some SMTP servers examine the ‘From’ field address for making sure that the email address contained in it is a legitimate one for that particular domain prior to sending the email (Lewis, 2008).

SMTP server contains three unique kinds of authentication techniques:

Anonymous Access: This entails that no username or password is needed

Basic Authentication: A user account and password is needed, and is sent out as plain text across the network. Moreover, it is suggested that TSL, Transport Layer Security, encryption be utilized with basic authentication for avoiding unauthorized identification of user names as well as passwords.

Integrated Windows Authentication: This feature entails that the user account and password extracted from the Active Directory is utilized during the authentication processes. At the receiver end, in order to receive the email, the mail server software uses either POP3 (Post Office Protocol 3) or IMAP (Internet Message Access Protocol). Working of POP3 is as follows:

1. The POP3 server receives the e-mail originating from an SMTP server
2. Then, the POP3 server analyzes the “To”, “Cc”, and “Bcc” field addresses in order to find out which server the email is supposed to reach.
3. The POP3 server then sends the mail to the “inbox” or “mailbox” for that address, only if the recipient email address is legitimate for that domain. However, if it is not a legitimate address, the POP3 server sends back an error message to the SMTP server.
4. Finally, when the user opens their mail client such as Outlook Express, the in-built software package checks the POP3 server for new email. Then, the address of the mail server may be seen within the configuration of POP3 server (Lewis, 2008).

POP3 allows three distinct types of authentication services in order to verify user connections at the POP3 services.

1. Local Window Account Authentication: This method is used if the server is not included as a part of the Active Directory, or if the user accounts are required to be stored at the server at which the POP3 services reside
2. Encrypted Password File Authentication: This method is used whenever the server is not utilizing Active Directory, or if the user accounts are required to be stored at the server at which the POP3 services reside
3. Active Directory Integrated Authentication: The e-mail server is a domain controller or a member server that is included in the Active Directory domain. Furthermore, IMTP is the latest protocol being used to receive emails, and is used by several mail server software packages in place of POP3 for receiving mails.

A newer and broadly-used function of certain mail server packages is the Mail Filtering feature. These are the mail servers that function as ‘spam detectors’, which analyze the inbound mail and inspects whether or not the mail is ‘spam’. Significantly, the aspects for determining whether the mail is “spam” are based on the package. Common factors are: keywords, letter combinations, the originating domain, etc (Lewis, 2008).

E-mail Programs: Commonly, there are certain popular email programs including Eudora Light, Outlook Express, Netscape Mail, etc. Al of these programs contains almost the same features, and allows a user to create, send, receive as well as organize their messages (Kawamata & Jiro, 2001).

How e-mails get around the Internet

Architectures and services

This section provides an overview of what exactly e-mail systems can do and the ways in which they are organized. E-mail systems typically comprises of two sub-systems: the user agents and the message transfer agents. The user agents allow people to read as well as send e-mails. The message transfer agents are responsible for moving the email messages from origin to target address. The user agents are nothing but local programs which offer a menu-based, command-based, or graphical method in order to interact with the email system. On the other hand, the message transfer agents are typically system daemons, which are processes running in the background. Their main role is to move emails through the system (Tanenbaum, 2005) (The FreeBSD Documentation Project, 2010) (AOM Software, 2010).

Typically, e-mail servers or systems perform five fundamental functions.

1. Composition: It refers to the process of creation of messages and answers for those messages. Even though any general text editor may be utilized for the message body, the system itself is capable of providing assistance for addressing and the several header fields that are attached to every message. For instance, while answering a message, the email system may extract the sender’s address from the incoming email and can automatically insert it at a proper place within the reply.
2. Transfer: It refers to the process of moving messages from the sender/ originator to the receiver. In large parts, this needs a connection to be established with the destination or some intermediate machine, producing the output of the message, and releasing the connection. Furthermore, the email system must perform this work automatically, without disturbing the user (Tanenbaum, 2005).
3. Reporting: Reporting deals with informing the sender of the message as to what happened to the message. Questions such as Was it rejected? Was it delivered? Was is lost?, etc are answered by the reporting process. Moreover, numerous applications are there wherein confirmation of delivery of the message is not only important but also necessary and may have legal significance.
4. Displaying: This function deals with displaying the incoming messages that is needed so that user can read their emails. Most of the times conversations are required or a special viewer should be invoked, for instance, if the message is a digitized voice or a PostScript file. Simple conversations as well as formatting are also sometimes attempted.
5. Disposition: Disposition is the last step and is related to what the receiver does with the message after he/she receives it. In this, possibilities include discarding it after reading, discarding it before reading, saving it, so on and so forth. Moreover, it must be possible to retrieve and re-read the saved messages, or forward them, or process them in other manners (Tanenbaum, 2005).

In addition to these fundamental services, certain email systems, particularly internal corporate ones, offer a variety of advanced features. Whenever a person is moving are they are away from their workplace for a period of time, they may wish to forward their emails; hence the system must be capable of doing this automatically. Indeed, almost every system allows its users to create mailboxes in order to store incoming emails. Commands are needed for creation and destruction of mailboxes, inspecting the contents of mailboxes, inserting and deleting messages from mailboxes, etc. Furthermore, corporate managers frequently find it necessary to send messages to each other and to each of their subordinates, clients, customers, or suppliers. As a result, a technique of mailing lists was developed, which is nothing but a list of email addresses. Whenever a message is sent out to the mailing list, identical copies of it are delivered to every recipient on the list. In essence, other advanced features include carbon copies (CC), blind carbon copies (BCC), secret or encrypted email, high priority email, and the power for secretaries to read as well as answer their bosses’ emails (Oricode, 2010) (Vleck, 2008) (Tanenbaum, 2005) (The FreeBSD Documentation Project, 2010). Emails are now being widely used within organizations and industries for intra-company communications. For this, it allows for far flung employees to communicate and cooperate on complex projects, even across many time zones. Furthermore, by eliminating most cues that are associated with age, rank, sex, etc, email debates are likely to focus on thoughts and ideas, and not on corporate status (Oricode, 2010) (AOM Software, 2010).

Particularly, a primary idea fundamental to email systems is the distinction between the ‘envelope’ and its contents. The envelope is used to encapsulate the message. The envelope contains all the important information required for transporting the message, like the destination address, security level, priority, all of which are unique from the message itself. The envelope is used by the message transfer agents for routing, similar to the working of a post office.

Every email is divided into 2 sections, namely the header section and the body section. The header part defines the control information for the user agents, such as the source and destination of the message, the time it was mailed, the person who created the message, etc (Tanenbaum, 2005). Next, the body of the message is totally for the human recipient and contains the main content of the message that may be plain text, or Multipurpose Internet Mail Extensions (MIME). MIME permits a sender’s mail server to accurately encode 8-bit binary files by using a mail system which supports only plain text. Moreover, a MIME enabled mail server first encodes binary data as text and the recipient’s mail server then decodes the text back to a binary file (Oricode, 2010).

Message formats

RFC 822: Email messages contain a primitive envelope, a number of header files, a blank line, and a message body. Every header field logically comprises of a line of ASCII text that contains the field name, a colon and a value. The primary header fields referred to the message transport is as follows:

To: this field indicates the DNS address of the primary receiver/ recipient. This can have multiple recipients also (Tanenbaum, 2005).

Cc (Carbon copy): This field specifies the email address of a secondary recipient (Tanenbaum, 2005). However, with respect to delivery, there is no difference between the primary and the secondary recipient.

Bcc (Blind carbon copy): This filed is similar to the Cc field, with only difference of the line being eliminated from every copy of original message being sent to the primary receiver and the secondary receiver (Tanenbaum, 2005). Moreover, this field enables users to send out copies of the original message to third party recipients without the primary as well as secondary recipients knowing about the action.

From: Indicates who created the message.

Sender: Indicates who sent the message; contains the e-mail address belonging to the actual sender. The ‘Sender:’ field is different from the ‘From:’ field (Tanenbaum, 2005). Received: The line that contains this field is included by the message transfer agent during the transfer route to the destination. This line stores the agent’s identity, the date and the time when the message was received, together with other additional information which may be used for detecting bugs within the routing system.

Return-Path: The final message transfer agent adds this field and indicates how the recipient can get back to the sender. Theoretically, this data may be derived from every ‘Received:’ header; however it is hardly filled in and only holds the sender’s address (Oricode, 2010) (Tanenbaum, 2005).

Server Requirements

A standalone computer that is running as a mail server must have ample disk space in order to store the messages. In cases where the computer is running GUI-intensive mail server software, such as an amount of commercial products, then the computer must have high memory and a high speed processor. For instance, the system requirements list of Microsoft Exchange Server indicates that the machine must have a 733 mHz processor, minimum of 1 GB disk space, and 512 MB RAM (Lewis, 2008) (AOM Software, 2010).

Cost: An issue

Cost could be an issue for a small business or a home user. In this case, there exist several open-source solutions which cost little to no money. For instance, the Apache servers consist of mail servers which are free of cost, and they also run on almost every common platform such as Windows, Linux, and UNIX. However, the disadvantage of these “cheap solutions” lies is their configuration is not as easy and do not have additional features in comparison to their commercial counterparts (Lewis, 2008) (Louwrens, 2003).

Windows Server 2003 as an efficient messaging solution

Both Exchange Server and Windows Server 2003 offer POP3 functionality to their users. Nonetheless, in Windows Server 2003 just the fundamental POP3 functions are provided to the user and administrator. This involves only a limited amount of messaging experience with availability of administrative features. Therefore, POP3 services are stated to be most ideal for small-scale organizations that require only the basic administration and messaging functionality. Additionally Exchange Server offers an enhanced collaboration and messaging environment to the administrator and the user. It also supports several Internet protocols. Microsoft introduced the E-mail services in Windows Server 2003. As aforementioned, the basic configuration needed for loading and running the email services includes the services of SMTP and POP3 (Louwrens, 2003) (AOM Software, 2010).

Supporting Technologies

Several supporting technologies are available in Microsoft technologies that enhance the emailing services in Windows Server 2003. Organizations that require additional collaboration capabilities and functionality utilize these technologies.

1. Free/ Busy information: The publishing of ‘Free/busy’ notification on a website is possible with Microsoft Outlook (Louwrens, 2003).
2. Public Key Infrastructure: For enabling secure mail communication with an organization, a PKI (Public Key Infrastructure) should be implemented. PKI certificates to digitally sign the mail messages prior to sending, is assigned to users. Mail communications among organizations need more complex security, so a third party certification authority is recommended. S/MIME is used at the client side in order to ensure that the mail is digitally signed as well as encrypted before sending.
3. Additional feature such as Windows share-point services, scalability features, and real-time communication server is also employed (Louwrens, 2003).

Internet Black Lists and White lists

Two of the most damaging and least effective techniques for combating spam are the white lists and the black lists. Commonly, these lists intend to harm innocent computer users and avoid crucial business emails from being delivered. If the user is sending emails from an email server residing on their computer, and the IP address is resides on one of the lists, then that may affect the user in two opposing ways:

1. The messages will not be delivered if the email server of a recipient verifies the IP addresses of inbound connection with those contained in the white and black lists
2. If the message successfully reaches the recipient, then the recipient is able to run anti-spam software which employs block lists in order to group the messages into spam mails. The sender’s email may be seen residing in a folder of spam mails or be permanently discarded and never be accessed by the recipient.

Black Lists

A black list is nothing but a list of spam users containing addresses as well as domains having spam email servers which the sender is aware of (Oricode, 2010). This list is used for blocking every email that arrives from particular servers across the Internet which is can be used to send spam mails. Examples of black lists are SpamCop and Open Relay Database. Almost every anti-spam product has its own black list (Oricode, 2010).

White Lists

These are exactly opposite in nature and functionality to black lists. White lists are a list of known, authorized and trusted email addresses as well as domains which are invariably allowed to send out emails, irrespective of the content in it. These lists are used to complying the senders to authenticate their identity before the delivery of emails, to the recipient (Oricode, 2010).

Conclusion

Therefore, the research study provided in this paper addresses every aspect related to the functioning of electronic mail systems. The topics covered in this paper clearly represent the in-depth study backed by the underlying technology and protocols, employed by the email systems. It also talked about how email systems are beneficial by presenting a detailed study of its operations and configuration on different clients. The research paper also allows its readers to gain knowledge of the requirements of an email server, what are the precise uses of the fields in the email message format, and what they should do if cost is a major issue while using mail servers in their business or home and personal use. The paper also accurately addresses the problem of messages can be sent to several recipient at the same time through the use of “To”, “Cc” and “Bcc” fields. The paper advices users that this problem can be solved by not sending out email messages to recipients to whom the messages are not personally addressed. Moreover, the paper also talked about the additional technologies that support electronic mail systems and servers, and the concept of black lists and white lists that are used for sending out emails to the concerned recipient by having knowledge of their identity. To conclude, e-mail is short for electronic mail or message that is sent between two devices. Besides computers, e-mails can be sent as well as received from portable and mobile devices like PDAs, cell phones, etc. With e-mails it is possible to communicate through personal and work-related mails having attachments for documents, photos, audio and video. Electronic mail systems are the simplest form of communication in today’s world and almost every person having access to the Internet depends on e-mail systems to send messages and stay in touch with the family, friends and business partners, across the world.

References

AOM Software. (2010). Category Communications / E-Mail Clients. Web.

IBM. (2006). Why E-mail Fails: A Survey of E-mail Outages. IBM Global Technology Services. Web.

Kawamata & Jiro. (2001). Electronic mail server in which electronic mail is processed. United States Patent. Web.

LearntheNet.com. (2010). How E-mail Works. LearntheNet.com. Web.

Lewis, J. (2008). Mail Servers. Scribd.com.

Louwrens, F. (2003). Implementing the Windows Server 2003 E-Mail Services. Inobits Consulting.

Oricode. (2010). Sending to Multiple E-mail Addresses. Oricode. Web.

Tanenbaum, A. (2005). Computer Networks (4th ed.). New Jersey, USA: Pearson Education.

The FreeBSD Documentation Project. (2010). Electronic Mail. The FreeBSD Documentation Project. Web.

Vleck, T. (2008). The History of Electronic Mail. Web.