Selected+E-mail+Protocols+(JB)

= Email Protocols - SMTP/IMAP/POP3 =

Background/Definitions

 * What is Email and Email Protocols?**

Email is defined as "a networking application that allows users to send and receive mail electronically." (FitzGerald, 2009, P.558). Email protocols are languages for specifying rules for how email will operate (FitzGerald, 2009).


 * How do Email Protocols work?**

To fully understand how email protocols work, you need to understand that email protocols are divided into two groups: email transfer protocols and email access protocols. The main email transfer protocol used to day is Simple Mail Transfer Protocol or SMTP (FitzGerald, 2009). SMTP works by sending transferring a new email message from an email client to its mail server or mail transfer agent and then is used to transfer the email message between mail transfer agents (FitzGerald, 2009). SMTP messages are composed of two parts: a header and a body (FitzGerald, 2009). The header section of an SMTP message is composed of such things as the source & destination email address, the date, and the email message subject (FitzGerald, 2009). The body section of an SMTP message is the email message itself (FitzGerald, 2009). Each element in the header and body of an SMTP message is transmitted as its own packet from the source mail transfer agent to the destination mail transfer agent and the destination mail transfer agent sends a packet received message to the source mail transfer agent so it will transmit the next element (FitzGerald, 2009). SMTP only provides the transmission method, not access to the email (FitzGerald, 2009).

In order for a email user to gain access to an email through their email client, the email client has to use email access protocols (FitzGerald, 2009). Currently, there are two main email access protocols: Post Office Protocol or POP and Internet Message Access Protocol or IMAP (FitzGerald, 2009).


 * What are the requirements for Email access?**

The minimum requirements for providing email access is having a two-tier client-server architecture in which the client has the email client/mail user agent on it and uses it to communicate with the mail server/mail transfer agent (FitzGerald, 2009). If you have ever used Microsoft Outlook or Mozilla Firebird to access your email, this two-tier structure was most likely used. However, many email clients are now web based and set up in a three-tier architecture involving a web browser client machine, a web server, and a mail server, with an example of this type of architecture shown below (FitzGerald, 2009).




 * Should I use IMAP or POP3 as my email access protocol?**

IMAP is typically the better email access protocol. IMAP offers both offline and online mailbox access modes, while POP only offers offline mailbox access standalone and can only offer some online mailbox access through the use of additional file management protocol (Gray, 1995). Since offline mode is more suited for users who access their email from one machine, this presents a major disadvantage for POP users compared to IMAP users who can access their complete mailboxes from multiple systems and can even share a mailbox with other users (Gray, 1995). IMAP even has a protocol called Internet Message Support Protocol that can help IMAP users configure online address books (Gray, 1995). IMAP is also can optimize online performances for low-speed connections (Gray, 1995).


 * Is there any new email/email protocol-related technology being developed?**

There are many email related technologies that are being researched and developed. For instance, there is research going on for developing a fax machine connected to the Internet that can email written letters to people (New Scientist 191, 2001). There is also research going on to develop an application that scans for emails missing required attachments before they are sent (New Scientist, 2006).

Abstract
In order gain more knowledge about email and email protocols, I decided to research two questions. I first decided to to research with email access protocol, IMAP or POP, was better for used in the business world. The second question I wanted to answer was what email/email protocol technology is being developed for the next generation. In order to gather my information, I pulled my research information from related textbooks and online sources such as research articles. I found that IMAP is typically better for use in the business world since it provide more functionality than POP. Also, I found that there are many email/email protocol-related technology being researched such as a missing email attachment program and each emailing through fax machines.