For most of us, the fact that email works is all that we need to know. However, if you're a true geek you need to know that following key points. If you are not a geek yet, by the time you finish with this page you will know more than most.
An e-mail message is nothing more than a simple text message. Even if the message includes graphics and multiple zip file attachments are still just simple text - Yes, you can actually look at a mail message with a simple editor like " notepad" if you where so inclined. For the most part a message consists of 3 key pieces: MESSAGE HEADERS, MESSAGE BODY, and MESSAGE ATTACHMENTS. Perhaps you may have heard the term "Base 64 Encoding"? It is by far the most accepted method for taking Binary Files and Attachments are converting them into simple text so that they can be mailed and later converted back to binary when they are received.
SMTP (Simple Mail Transfer Protocol) and POP3 (Post Office Protocol) are 2 different programs that run on an Internet Server they actually SEND and RECEIVE the mail respectively. The only thing that you really need to know is that SMTP = SENDING while POP3 = RECEIVING.
If you really want to "know it all" then you might be interested to learn what a PORT is. Imagine "ports" to be a wall of numbered pigeon holes between the computer and the outside world. An SMTP program normally watches PORT 25 while POP3 normally watches port 110 for arriving instructions.
That didn't hurt too much did it?
This help article applies to Intellect 3