When you send an e-mail from your computer, the data is sent from your computer to an SMTP server. The SMTP server then searches for the correct POP3 server and sends your e-mail to that server, where it waits until your intended recipient retrieves it.
E-mail Accounts
E-mail accounts are available through many different sources. When you get an e-mail account, you will be given a two part e-mail address, in this form: username@domain.name. The first part, username identifies you on your network, differentiating you from all the other users on the network. The second part, domain.name is used to identify your specific network. The username must be unique within your network, just as the domain name must be unique among all the other networks on the Internet. However, user names are not unique outside of their networks; it is possible for two users on two different networks to share user names. One of the first things that you will do when you are setting up your e-mail is to enter your email address into your e-mail client program. Your e-mail client is the program that you will use to send and receive e-mails.
POP and SMTP
After your e-mail client knows your e-mail address, it's going to need to know where to look for incoming e-mail and where to send outgoing e-mail. Your incoming e-mails are going to be on a computer called a POP server. The POP server usually named something like pop.smallnetwork.net or ail.smallnetwork.net has a file on it that is associated with your e-mail address and which contains e-mails that have been sent to you from someone else. POP stands for post office protocol. Your outgoing e-mails will be sent to a computer called a SMTP server. This server named smtp.smallnetwork.net will look at the domain name contained in the e-mail address of any e-mails that you send, then will perform a DNS lookup to determine which POP3 server it should send the e-mail to. SMTP stands for simple mail transfer protocol. When you start up your e-mail client, a number of things happen:
The first thing to note is that you do not send a password to the SMTP server. SMTP is an old protocol, designed in the early days of e-mail, at a time when almost everyone on the Internet knew each other personally. The protocol was written with the assumption that everyone who would be using it would be trustworthy, so SMTP doesn't check to ensure that you are you. Most SMTP servers use other methods to authenticate users, but in theory anyone can use any SMTP server to send e-mail. The second thing to note is that, when you send your secret password to the POP server, you send it in a plain-text format. It may be hidden by little asterisks on your computer screen, but it is transmitted through the network in an easily readable format. Anyone who is monitoring traffic on the network using a packet sniffer, for instance will be able to clearly see your password. You may feel certain that your network is safe, but you have little control over what might be happening on any other network through which your data may pass. The third, and possibly most important thing that you need to know about your e-mails, is that they are just like your password transmitted and stored in a plain-text format. It is possible that they may be monitored any time they are transferred from the server to your computer. This all adds up to one truth that e-mail is not a secure method of transferring information.
Web Mail
A second option for e-mail is to use a web based e-mail account. This will allow you to use a web browser to check your e-mail. Since the e-mail for these accounts is normally stored on the web e-mail server not on your local computer it is very convenient to use these services from multiple computers. It is possible that your ISP (Internet Service Provider) will allow you to access your e-mail through both POP and the web. However, you must remember that web pages are cached or stored on local computers, sometimes for significant lengths of time. If you check your e-mail through a web based system on someone else's computer, there is a good chance that your e-mails will be accessible to someone else who uses that computer. Web based e-mail accounts are often free and easy to get. This means that they offer an opportunity for you to have several identities online. You can, for instance, have one e-mail address that you use only for friends and another that is only for relatives. This is usually considered acceptable, as long as you are not intentionally intending to defraud anyone.
E-mail Accounts
E-mail accounts are available through many different sources. When you get an e-mail account, you will be given a two part e-mail address, in this form: username@domain.name. The first part, username identifies you on your network, differentiating you from all the other users on the network. The second part, domain.name is used to identify your specific network. The username must be unique within your network, just as the domain name must be unique among all the other networks on the Internet. However, user names are not unique outside of their networks; it is possible for two users on two different networks to share user names. One of the first things that you will do when you are setting up your e-mail is to enter your email address into your e-mail client program. Your e-mail client is the program that you will use to send and receive e-mails.
POP and SMTP
After your e-mail client knows your e-mail address, it's going to need to know where to look for incoming e-mail and where to send outgoing e-mail. Your incoming e-mails are going to be on a computer called a POP server. The POP server usually named something like pop.smallnetwork.net or ail.smallnetwork.net has a file on it that is associated with your e-mail address and which contains e-mails that have been sent to you from someone else. POP stands for post office protocol. Your outgoing e-mails will be sent to a computer called a SMTP server. This server named smtp.smallnetwork.net will look at the domain name contained in the e-mail address of any e-mails that you send, then will perform a DNS lookup to determine which POP3 server it should send the e-mail to. SMTP stands for simple mail transfer protocol. When you start up your e-mail client, a number of things happen:
- The client opens up a network connection to the POP server
- The client sends your secret password to the POP server
- The POP server sends your incoming e-mail to your local computer
- The client sends your outgoing e-mail to the SMTP server.
The first thing to note is that you do not send a password to the SMTP server. SMTP is an old protocol, designed in the early days of e-mail, at a time when almost everyone on the Internet knew each other personally. The protocol was written with the assumption that everyone who would be using it would be trustworthy, so SMTP doesn't check to ensure that you are you. Most SMTP servers use other methods to authenticate users, but in theory anyone can use any SMTP server to send e-mail. The second thing to note is that, when you send your secret password to the POP server, you send it in a plain-text format. It may be hidden by little asterisks on your computer screen, but it is transmitted through the network in an easily readable format. Anyone who is monitoring traffic on the network using a packet sniffer, for instance will be able to clearly see your password. You may feel certain that your network is safe, but you have little control over what might be happening on any other network through which your data may pass. The third, and possibly most important thing that you need to know about your e-mails, is that they are just like your password transmitted and stored in a plain-text format. It is possible that they may be monitored any time they are transferred from the server to your computer. This all adds up to one truth that e-mail is not a secure method of transferring information.
Web Mail
A second option for e-mail is to use a web based e-mail account. This will allow you to use a web browser to check your e-mail. Since the e-mail for these accounts is normally stored on the web e-mail server not on your local computer it is very convenient to use these services from multiple computers. It is possible that your ISP (Internet Service Provider) will allow you to access your e-mail through both POP and the web. However, you must remember that web pages are cached or stored on local computers, sometimes for significant lengths of time. If you check your e-mail through a web based system on someone else's computer, there is a good chance that your e-mails will be accessible to someone else who uses that computer. Web based e-mail accounts are often free and easy to get. This means that they offer an opportunity for you to have several identities online. You can, for instance, have one e-mail address that you use only for friends and another that is only for relatives. This is usually considered acceptable, as long as you are not intentionally intending to defraud anyone.
