Day 22: How email works

The first email sent...ever:

• sent in 1971 by an engineer named Ray Tomlinson


• Prior to this, you could only send messages to users on a single machine


• Tomlinson discovered the ability to send messages to other machines on the Internet, using the @ sign to designate the receiving machine
  
  

Email messages are sent using 4 basic steps:

1. Sender's email program or Web browser sends the message to the sender's email sever


2. Sender's email server sends that message to the recipient's email server


3. Recipient's email server recieves the message, filters junk mail, and stores the message so it may be retrieved later.


4. Recipient's email program downloads the message from the recipient's email server to the recipient's computer and removes it from the server.


Other important email vocabulary:

email client: programs used to access emails. Connect to email server so user can send/recieve mail
- stand alone clients: Microsoft Outlook
- clients that appear in a webpage: Yahoo, Hotmail

SMTP server (Simple Mail Transfer Protocol): handles outgoing mail

POP3/IMAP server: handle incoming mail

Diagram of SMTP and POP3 servers

HowStuffWorks "How E-Mail Works"