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Email: Overview. E-mail has been around since the late 1970’s Started on UNIX systems Was text only for quite some time. Just like web pages, email needs some software for you to receive, view, edit, and send messages. MS Outlook or Outlook Express – typical on Windows machines.
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Email: Overview • E-mail has been around since the late 1970’s • Started on UNIX systems • Was text only for quite some time. • Just like web pages, email needs some software for you to receive, view, edit, and send messages. • MS Outlook or Outlook Express – typical on Windows machines. • PINE – text only, often on UNIX machines like Pegasus • Web browsers – Often have mail handling facilities • Is becoming more prevalent in the workplace. • The most important thing in most work situations is communication
Structure of the Message • Header: • Contains routing information X-Apparently-To: klngarfield@yahoo.com via web20307.mail.yahoo.com; 24 Aug 2001 05:14:53 -0700 (PDT) Received: from 132.170.192.28 (EHLO ntmailserver.ist.ucf.edu) (132.170.192.28) by mta422.mail.yahoo.com with SMTP; 24 Aug 2001 05:14:53 -0700 (PDT) Received: by ntmail.ist.ucf.edu with Internet Mail Service (5.5.2653.19) id <QPPF0LNC>; Fri, 24 Aug 2001 08:14:40 -0400 Message-ID: <DC36C1DDC3CED211862E006008A361BE845CC2@ntmail.ist.ucf.edu> From: "Garfield | Block Address | Add to Address Book To: 'Keith Garfield' <klngarfield@yahoo.com> Subject: RE: Welcome to Yahoo! Mail Date: Fri, 24 Aug 2001 08:14:39 -0400
Structure of the Message • Body: • Contains the message itself • Can contain mini-header information if forwarded or replied mail. • great > -----Original Message----- > From: Keith Garfield [SMTP:klngarfield@yahoo.com] > Sent: Friday, August 24, 2001 8:14 AM > To: Garfield, Keith > Subject: RE: Welcome to Yahoo! Mail > > thanks > --- "Garfield, Keith" <kgarfiel@ist.ucf.edu> wrote: > > > > > > > -----Original Message----- > > > From: Keith Garfield [SMTP:klngarfield@yahoo.com] > > > Sent: Friday, August 24, 2001 5:49 AM > > > To: kgarfiel@ist.ucf.edu > > > Subject: Fwd: Welcome to Yahoo! Mail > > >
Email Formats • Text (late 19070’s) • The old standard. • Literally allows only text messages. • Other formats have to be encoded into the message (uuencode , uudecode on UNIX machines) • MIME (1991) • Multi-Purpose Internet Mail Extension. • Allows any format file to be attached to the basic text message. • User no longer needs to encode and decode message formats. • Attaching items to the basic message is easily done using GUI tools. • HTML • This is the same format that web pages use. • The idea is that email viewers can be as graphically rich as browsers. • Security issues with running scripts.
Email Delivery Methods • SMTP - Simple Mail Transfer Protocol. • This moves the mail from mail server to mail server. • Deals only with how to move messages between two machines. • Is an end-to-end protocol • Sending and receiving machines communicate directly. • Sender can immediately verify that the receiver did indeed get the message. • Sender can hold the email until the receiver is ready to receive it. • Contrast with “best effort” transmission methods that simply send the message to “the next machine” without giving the sender information as to whether the receiver was actually reached. • Uses a command-response protocol • The sender identifies itself and all recipients and then sends the message • Each recipient responds with acknowledgement type messages • Sender and receiver stay synchronized • Individual “bad” receivers can be discontinued.
Email Delivery Methods • POP - Post Office Protocol. • Think of this as a traditional post office in the real world. • Allows you to work “offline” and only connect to the mail server when sending/receiving. • When you connect, mail moves from mail server to your machine. • Messages sent to your machine are removed from the server. • IMAP - Internet Message Access Protocol. • Allows a constant access to the mail server. • Message viewed by you still reside on the mail server. • HTML – HyperText Markup Language • Your mail is literally a web page. • Hotmail, Yahoo, etc use this type of protocol. • Note the protocols used: Mail is still sent from sending to receiving servers via SMTP, but mil is viewed by you using HTTP.
Email Diagram You Them Mail Server Mail Server Gateway Gateway
Email Usage Tips • Don’t let the attachments open automatically. • Many viruses are spread through email attachments, but the attachment must be opened to attack your machine. • Don’t send or reply to large mailing lists unless you mean it. • Baby announcements, retirements, and “I agree!” are the worst culprits. • Don’t be afraid to delete. • If you need to keep messages you can create sub-folders and store them by topic. • Don’t be afraid to edit the content of the original message when replying. • Be careful of style • ALL CAPS IS YELLING. • A friendly joke can seem like an attack without the body language to go with it.