1. Email (Electronic Mail) Most popular use of Internet technology Advantages Disadvantages Setting up an email account Your email account –User id and password –Inbox/mailbox Mail Clients (or Mailers)

2. Dissection of Email Address sjones@falcon.harvard.edu userid or username Host name Institutional Site Name Top-level Domain name Specific General

3. Top Level Domain Names (US) com edu gov int org net mil Commercial business Educational institution Governmental agency International entity Non-profit organization Networking organization U.S. military

4. Some Country Top Level Domain Names au (Australia) ca (Canada) cl (Chile) de (Germany) es (Spain) fr (France) hk (Hong Kong) jp (Japan) nl (Netherlands) uk (United Kingdon) us (United States) za (South Africa)

5. Demonstrate email Pine, Web-based Netscape Send and receive Addressbook Netscape (send & receive attachments)

6. Netiquette Always have a subject Do not use ALL CAPS Expression and Inflection Smileys/Emoticons :-), 8-(, :-{D Jokes, chain letters, etc. Responding to email Appropriate formality End messages with your name

7. Multipurpose Internet Mail Extensions Usually email consists of ASCII text MIME allows for a variety of files to be sent & received as attachments Files can often times be viewed in real time Security problems can arise Be careful of sending large files when the recipient is not expecting it.

8. Web-based Email A Web protocol for Web pages Also used when you use Web-based email services (i.e. yahoo, hotmail) You log into your account, read your mail, manage mail, and send mail using the Web.

9. Email via Post Office Protocol 3 Key point: Email is downloaded to the local machine and not kept on the server. POP/SMTP Mail Servers Bob’s POP account Sue’s POP account Bob’s Mail Client Sue’s Mail Client SMTP POP SMTP POP SMTP

10. Email via Internet Message Access Protocol Key point: Email is kept on the mail server (online), and can be read* from the local machine. IMAP/SMTP Mail Servers Bob’s IMAP account Sue’s IMAP account Bob’s Mail Client Sue’s Mail Client SMTP IMAP SMTP IMAP SMTP

11. How Email Works SMTP (Simple Mail Transfer Protocol) on your mail server –Verifies the DNS address –If successful, prepares the mail and sends it out When message is sent it is broken down into small packets and reassembled. Email can ‘bounce’ if: –Bad user account name or domain name –Domain name server is down for several days –Other reasons (i.e. message too big)