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)

Dissection of Email Address

sjones@falcon.harvard.edu

userid orusername

Host name InstitutionalSite Name

Top-levelDomain name

Specific General

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

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)

Demonstrate email

• Pine, Web-based Netscape

• Send and receive

• Addressbook

• Netscape (send & receive attachments)

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

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.

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.

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’sPOP

account

Bob’sMail Client

Sue’sMail Client

SMTPPOP

SMTP

POP

SMTPSMTP

Email via Internet Message Access Protocol

Key point:Email is kept on the mailserver (online), and can be read* from the local machine.

IMAP/SMTP Mail Servers

Bob’s IMAP

account

Sue’sIMAP

account

Bob’sMail Client

Sue’sMail Client

SMTPIMAP

SMTP

IMAP

SMTPSMTP

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)